Pyridazinone compound and use thereof

ABSTRACT

A pyridazinone compound represented by the formula (I) 
     
       
         
         
             
             
         
       
     
     has excellent effect on weed control and is useful as an active ingredient of herbicides.

This application is a Divisional of U.S. application Ser. No.13/426,894, filed Mar. 22, 2012, which is a Continuation of U.S.application Ser. No. 12/225,233, filed Sep. 17, 2008, now U.S. Pat. No.8,541,414, which is a national stage application of Internationalapplication No. PCT/JP2007/055579, filed Mar. 13, 2007.

TECHNICAL FIELD

The present invention relates to pyridazinone compounds and herbicidescomprising thereof.

BACKGROUND ART

A certain type of pyridazinone compound is known in J. Heterocycl.Chem., vol. 42, pp. 427-435(2005).

However, said pyridazinone compound does not have enough weedcontrolling effect.

The subject of the present invention is to provide the compound with anexcellent effect on weed control.

DISCLOSURE OF INVENTION

After extensive investigation, the present inventors discovered thepyridazinone compounds represented by the formula (I) have an excellenteffect on weed control to complete the present invention.

The present invention is as the following.

(1) A pyridazinone compound represented by the formula (I) (hereinafterrefer to the present compound),

wherein in formula, R¹ represents a C₁₋₆ alkyl group or a (C₁₋₆alkyloxy) C₁₋₆ alkyl group,

R² represents a hydrogen atom or a C₁₋₆ alkyl group,

G represents a hydrogen atom, a group represented by formula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, L represents an oxygen or a sulfur atom,

R³ represents a C₁₋₆ alkyl group, a C₃₋₈ cycloalkyl group, a C₂₋₆alkenyl group, a C₂₋₆ alkynyl group, a C₆₋₁₀ aryl group, a (C₆₋₁₀ aryl)C₁₋₆ alkyl group, a C₁₋₆ alkyloxy group, a C₃₋₈ cycloalkyloxy group, aC₂₋₆ alkenyloxy group, a C₂₋₆ alkynyloxy group, a C₆₋₁₀ aryloxy group, a(C₆₋₁₀ aryl) C₁₋₆ alkyloxy group, an amino group, a C₁₋₆ alkylaminogroup, a C₂₋₆ alkenylamino group, a C₆₋₁₀ arylamino group, di(C₁₋₆alkyl)amino group, di(C₂₋₆ alkenyl)amino group, a (C₁₋₆ alkyl) (C₆₋₁₀aryl)amino group or a three- to eight-membered nitrogen containingheterocyclic ring group,

R⁴ represents a C₁₋₆ alkyl group, a C₆₋₁₀ aryl group, a C₁₋₆ alkylaminogroup or di(C₁₋₆ alkyl)amino group and

R⁵ and R⁶ may be same or different and represent a C₁₋₆ alkyl group, aC₃₋₈ cycloalkyl group, a C₂₋₆ alkenyl group, a C₆₋₁₀ aryl group, a C₁₋₆alkyloxy group, a C₃₋₈ cycloalkyloxy group, a C₆₋₁₀ aryloxy group, a(C₆₋₁₀ aryl) C₁₋₆ alkyloxy group, a C₁₋₆ alkylthio group, C₁₋₆alkylamino group or di(C₁₋₆ alkyl)amino group,

here, any group represented by R³, R⁴, R⁵ and R⁶ may be substituted withat least one halogen atom and a C₃₋₈ cycloalkyl group, a C₆₋₁₀ arylgroup, an aryl moiety of a (C₆₋₁₀ aryl) C₁₋₆ alkyl group, a C₃₋₈cycloalkyloxy group, a C₆₋₁₀ aryloxy group, an aryl moiety of a (C₆₋₁₀aryl) C₁₋₆ alkyloxy group, an aryl moiety of a C₆₋₁₀ arylamino group, anaryl moiety of a (C₁₋₆ alkyl) (C₆₋₁₀ aryl)amino group and a three- toeight-membered nitrogen containing heterocyclic ring group may besubstituted with at least one C₁₋₆ alkyl group),

Z¹ represents a C₁₋₆ alkyl group,

Z² represents a C₁₋₆ alkyl group, n represents 0, 1, 2, 3 or 4 and eachof Z² may be same or different when n represents an integer of 2 ormore,

and a sum of the number of carbon atoms in the group represented by Z¹and that in the group represented by Z² is equal to 2 or more.

(2) The pyridazinone compound according to (1), wherein n is an integerequal to 1 or more.(3) The pyridazinone compound according to (1), wherein n is 0 and Z¹ isa C₂₋₆ alkyl group.(4) The pyridazinone compound according to (1), wherein n is 1 or 2 andZ² is (a) substituent(s) on 4- and/or 6-position of a benzene ring.(5) The pyridazinone compound according to (1), (2) or (4), wherein Z¹is a C₁₋₃ alkyl group and Z² is a C₁₋₃ alkyl group.(6) The pyridazinone compound according to any one of (1) to (5),wherein G represents a hydrogen atom, a group represented by formula,

a group represented by formula

or a group represented by formula,

wherein in formula,

R^(3b) represents a C₁₋₆ alkyl group, a C₃₋₈ cycloalkyl group, a C₂₋₆alkenyl group, a C₂₋₆ alkynyl group, a C₆₋₁₀ aryl group, a (C₆₋₁₀ aryl)C₁₋₆ alkyl group, a C₁₋₆ alkyloxy group, a C₃₋₈ cycloalkyloxy group, aC₆₋₁₀ aryloxy group, a (C₆₋₁₀ aryl) C₁₋₆ alkyloxy group, a C₁₋₆alkylamino group, a C₆₋₁₀ arylamino group or di(C₁₋₆ alkyl)amino group,

R^(4b) represents a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group and

R^(5b) and R^(6b) may be same or different and represent a C₁₋₆ alkylgroup, a C₁₋₆ alkyloxy group, a C₆₋₁₀ aryloxy group or a C₁₋₆ alkylthiogroup,

here, any group represented by R^(3b), R^(4b), R^(4b), R^(5b) and R^(6b)may be substituted with at least one halogen atom and a C₃₋₈ cycloalkylgroup, a C₆₋₁₀ aryl group, an aryl moiety of a (C₆₋₁₀ aryl) C₁₋₆ alkylgroup, a C₃₋₈ cycloalkyloxy group, a C₆₋₁₀ aryloxy group, an aryl moietyof a (C₆₋₁₀ aryl) C₁₋₆ alkyloxy group and an aryl moiety of a C₆₋₁₀arylamino group may be substituted with at least one C₁₋₆ alkyl group.

(7) The pyridazinone compound according to any one of (1) to (5),wherein G represents a hydrogen atom, a group represented by formula,

or a group represented by formula,

wherein in formula,

R^(3a) represents a C₁₋₆ alkyl group, a C₃₋₈ cycloalkyl group, a C₆₋₁₀aryl group, a C₁₋₆ alkyloxy group or di(C₁₋₆ alkyl)amino group and

R^(4a) represents a C₁₋₆ alkyl group,

here, any group represented by R^(3a) and R^(4a) may be substituted withat least one halogen atom and a C₃₋₈ cycloalkyl group and a C₆₋₁₀ arylgroup may be substituted with at least one C₁₋₆ alkyl group.

(8) The pyridazinone compound according to any one of (1) to (7),wherein R² is a hydrogen atom or a C₁₋₃ alkyl group.(9) The pyridazinone compound according to any one of (1) to (7),wherein R² is a hydrogen atom or a methyl group.(10) The pyridazinone compound according to any one of (1) to (9),wherein R¹ is a C₁₋₃ alkyl group or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group.(11) A herbicide comprising the pyridazinone compound according to anyone of (1) to (10) as an active ingredient.(12) A weed controlling method comprising a step, in which an effectiveamount of the pyridazinone compound according to any one of (1) to (10)is applied to weeds or soil where weeds are grown.(13) Use of the pyridazinone compound according to any one of (1) to(10) for weed control.(14) A compound represented by the formula (II):

wherein in formula, R⁷ represents a C₁₋₆ alkyl group, R¹, R², Z¹, Z² andn have the same meaning as defined in (1).(15) A compound represented by the formula (VI):

wherein in formula, R⁹ represents a C₁₋₆ alkyl group, R¹, R², Z¹, Z² andn have the same meaning as defined in (1).

In substituents represented by R¹, R², R³, R⁴, R⁵, R⁶, Z¹ and Z² in theformula (I) of the present invention,

a C₁₋₆ alkyl group denotes an alkyl group with the number of carbonatoms from 1 to 6 and includes, for example, a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, a sec-butyl group, a tert-butyl group, a pentyl group, asec-pentyl group, an isopentyl group, a neopentyl group, a hexyl group,an isohexyl group, etc.,

a C₃₋₈ cycloalkyl group denotes a cycloalkyl group with the number ofcarbon atoms from 3 to 8 and includes, for example, a cyclopropyl group,a cyclopentyl group, a cyclohexyl group, etc.,

a C₂₋₆ alkenyl group denotes an alkenyl group with the number of carbonatoms from 2 to 6 and includes, for example, an allyl group, a1-buten-3-yl group, a 3-buten-1-yl group, etc.,

a C₂₋₆ alkynyl group denotes an alkynyl group with the number of carbonatoms from 2 to 6 and includes, for example, a propargyl group,2-butynyl group, etc.,

a C₆₋₁₀ aryl group denotes an aryl group with the number of carbon atomsfrom 6 to 10 and includes, for example, a phenyl group, a naphthylgroup, etc.,

a (C₆₋₁₀ aryl) C₁₋₆ alkyl group denotes a C₁₋₆ alkyl group substitutedwith a C₆₋₁₀ aryl group and includes, for example, a benzyl group, aphenethyl group, etc.,

a C₁₋₆ alkyloxy group denotes an alkyloxy group with the number ofcarbon atoms from 1 to 6 and includes, for example, a methoxy group, anethoxy group, a propoxy group, an isopropoxy group, etc.,

a C₃₋₈ cycloalkyloxy group denotes a cycloalkyloxy group with the numberof carbon atoms from 3 to 8 and includes, for example, a cyclopropyloxygroup, a cyclopentyloxy group, etc.,

a C₂₋₆ alkenyloxy group denotes an alkenyloxy group with the number ofcarbon atoms from 2 to 6 and includes, for example, a vinyloxy group, anallyloxy group, etc.,

a C₂₋₆ alkynyloxy group denotes an alkynyloxy group with the number ofcarbon atoms from 2 to 6 and includes, for example, a propargyloxygroup, 2-butynyloxy group, etc.,

a C₆₋₁₀ aryloxy group denotes an aryloxy group with the number of carbonatoms from 6 to 10 and includes, for example, a phenoxy group, anaphthoxy group, etc.,

a (C₆₋₁₀ aryl) C₁₋₆ alkyloxy group denotes a C₁₋₆ alkyloxy groupsubstituted with a C₆₋₁₀ aryl group and includes, for example, abenzyloxy group, a phenethyloxy group, etc.,

a C₁₋₆ alkylamino group denotes an alkylamino group with the number ofcarbon atoms from 1 to 6 and includes, for example, a methylamino group,an ethylamino group, etc.,

a C₂₋₆ alkenylamino group denotes an alkenylamino group with the numberof carbon atoms from 2 to 6 and includes, for example, an allylaminogroup, a 3-butenylamino group, etc.,

a C₆₋₁₀ arylamino group denotes an arylamino group with the number ofcarbon atoms from 6 to 10 and includes, for example, a phenylaminogroup, a naphthylamino group, etc.,

a di(C₁₋₆ alkylamino group denotes an amino group substituted with twosame or different C₁₋₆ alkyl groups and includes, for example, adimethylamino group, a diethylamino group, an N-ethyl-N-methylaminogroup, etc.,

a di(C₂₋₆ alkenyl)amino group denotes an amino group substituted withtwo same or different C₂₋₆ alkenyl groups and includes, for example, adiallylamino group, a di(3-butenyl)amino group, etc.,

a (C₁₋₆ alkyl) (C₆₋₁₀ aryl)amino group denotes an amino groupsubstituted with a C₁₋₆ alkyl group and a C₆₋₁₀ aryl group and includes,for example, a methylphenylamino group, an ethylphenylamino group, etc.,

a C₁₋₆ alkylthio group denotes an alkylthio group with the number ofcarbon atoms from 1 to 6 and includes, for example, a methylthio group,an ethylthio group, a propylthio group, an isopropylthio group, etc.,

a (C₁₋₆ alkyloxy) C₁₋₆ alkyl group denotes a C₁₋₆ alkyl groupsubstituted with a C₁₋₆ alkyloxy group and includes, for example, amethoxyethyl group, an ethoxyethyl group, etc., and

a three- to eight-membered nitrogen containing heterocyclic ring groupdenotes an aromatic or alicyclic three- to eight-membered heterocyclicring group comprising one to three nitrogen atoms as a ring member atom(s) and optionally comprising one to three oxygen and/or sulfur atom (s)as a ring member atom (s) and includes, for example, a 1-pyrazolylgroup, a 2-pyridyl group, a 2-pyrimidinyl group, a 2-thiazolyl group, apyrrolidino group, a piperidino group, a morpholino group, etc.

The group represented by R³, R⁴, R⁵ and R⁶ may be substituted with atleast one halogen atom and such halogen atom includes, for example, afluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the group represented by R³, R⁴, R⁵ and R⁶, a C₃₋₈ cycloalkyl group,a C₆₋₁₀ aryl group, an aryl moiety of a (C₆₋₁₀ aryl) C₁₋₆ alkyl group, aC₃₋₈ cycloalkyloxy group, a C₆₋₁₀ aryloxy group, an aryl moiety of a(C₆₋₁₀ aryl) C₁₋₆ alkyloxy group, an aryl moiety of a C₆₋₁₀ arylaminogroup, an aryl moiety of a (C₁₋₆ alkyl) (C₆₋₁₀ aryl)amino group and athree- to eight-membered nitrogen containing heterocyclic ring group maybe substituted with a C₁₋₆ alkyl group and such a C₁₋₆ alkyl groupincludes, for example, a methyl group, an ethyl group, a propyl group, abutyl group and the like.

Among the present compound, the compound represented by the formula(I-a), of which G is a hydrogen atom may take place in a form oftautomers represented by the formulas (I-a′) and (I-a″). The compoundrepresented by the formula (I-a) includes all of such tautomers and amixture of any two or more of them.

The salt of the compound represented by the formula (I-a) can be alsoobtained, for example, by mixing the compound represented by the formula(I-a) with an inorganic base (for example, hydroxide, carbonate,hydrogen carbonate, acetate, hydride or others of an alkali metal(lithium, sodium, potassium, etc.); hydroxide, hydride or others of analkali earth metal (magnesium, calcium, barium, etc.) or ammonia); anorganic base (for example, dimethylamine, triethylamine, piperazine,pyrrolidine, piperidine, 2-phenylethylamine, benzylamine, ethanolamine,diethanolamine, pyridine, collidine, etc.) or a metal alkoxide (forexample, sodium methoxide, potassium tert-butoxide, magnesium methoxide,etc.). The present invention includes agriculturally acceptable salts ofthe compounds represented by formula (I-a).

When the present compound has one or more asymmetric centers, thepresent compound takes place in a form of two or more stereoisomers (forexample, enantiomers, diastereomers or the like). The present compoundincludes all of such stereoisomers and a mixture of any two or more ofthem.

When the present compound has geometric isomerism based on a double bondor the like, said compound also takes place in a form of two or moregeometric isomers (for example, each isomer of E/Z- ortrans/cis-isomers, each isomer of S-trans/S-cis-isomers or others). Thepresent compound includes all of such geometric isomers and a mixture ofany two or more of them.

Preferred embodiments of the present compounds include, for example, thefollowing embodiment among the present compounds.

The pyridazinone compound in the formula (I), wherein n is an integer of1 or more.

The pyridazinone compound in the formula (I), wherein n is 0 and Z¹ is aC₂₋₆ alkyl group.

The pyridazinone compound in the formula (I), wherein n is 1 or 2 and Z²is bonded at a 4- and/or 6-position of the benzene ring.

The pyridazinone compound in the formula (I), wherein G is a hydrogenatom, a group represented by formula,

a group represented by formula,

or a group represented by formula,

(wherein in formula,

R^(3b) represents a C₁₋₆ alkyl group, a C₃₋₈ cycloalkyl group, a C₂₋₆alkenyl group, a C₂₋₆ alkynyl group, a C₆₋₁₀ aryl group, a (C₆₋₁₀ aryl)C₁₋₆ alkyl group, a C₁₋₆ alkyloxy group, a C₃₋₈ cycloalkyloxy group, aC₆₋₁₀ aryloxy group, a (C₆₋₁₀ aryl) C₁₋₆ alkyloxy group, a C₁₋₆alkylamino group, a C₆₋₁₀ arylamino group or di(C₁₋₆ alkyl)amino group,

R^(4b) represents a C₁₋₆ alkyl group or a C₆₋₁₀ aryl group and

R^(5b) and R^(6b) may be same or different and represent a C₁₋₆ alkylgroup, a C₁₋₆ alkyloxy group, a C₆₋₁₀ aryloxy group or a C₁₋₆ alkylthiogroup,

here, any group represented by R^(3b), R^(4b), R^(5b) and R^(6b) may besubstituted with at least one halogen atom and a C₃₋₈ cycloalkyl group,a C₆₋₁₀ aryl group, an aryl moiety of a (C₆₋₁₀ aryl) C₁₋₆ alkyl group, aC₃₋₈ cycloalkyloxy group, a C₆₋₁₀ aryloxy group, an aryl moiety of a(C₆₋₁₀ aryl) C₁₋₆ alkyloxy group and an aryl moiety of a C₆₋₁₀ arylaminogroup may be substituted with at least one C₁₋₆ alkyl group.)

The pyridazinone compound in the formula (I), wherein G is a hydrogenatom, a group represented by formula,

or a group represented by formula,

(wherein in formula,

R^(3a) represents a C₁₋₆ alkyl group, a C₃₋₈ cycloalkyl group, a C₆₋₁₀aryl group, a C₁₋₆ alkyloxy group or a di(C₁₋₆ alkyl)amino group and

R^(4a) represents a C₁₋₆ alkyl group,

here, any group represented by R^(3a) and R^(4a) may be substituted withat least one halogen atom and a C₃₋₈ cycloalkyl group and a C₆₋₁₀ arylgroup may be substituted with at least one C₁₋₆ alkyl group.)

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group.

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a C₁₋₃ alkyl group.

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a methyl group.

The pyridazinone compound in the formula (I), wherein Z¹ is a C₁₋₃ alkylgroup and Z² is a C₁₋₃ alkyl group.

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom ora C₁₋₃ alkyl group.

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom ora methyl group.

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a C₁₋₃ alkyl group and G is a hydrogen atom, a group representedby formula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned).

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a C₁₋₃ alkyl group and G is a hydrogen atom, a group representedby formula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned).

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a methyl group, G is a hydrogen atom, a group represented byformula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned).

The pyridazinone compound in the formula (I), wherein R² is a hydrogenatom or a methyl group and G is a hydrogen atom, a group represented byformula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or aC₁₋₃ alkyl group and G is a hydrogen atom, a group represented byformula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom ora C₁₋₃ alkyl group and G is a hydrogen atom, a group represented byformula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or amethyl group and G is a hydrogen atom, a group represented by formula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or amethyl group and G is a hydrogen atom, a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned.)

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom orC₁₋₃ alkyl group,

n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom orC₁₋₃ alkyl group and G is a hydrogen atom, a group represented byformula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned),n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or aC₁₋₃ alkyl group, G is a hydrogen atom, a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned),n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or amethyl group,

n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or amethyl group, G is a hydrogen atom, a group represented by formula,

a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3b), R^(4b), R^(5b) and R^(6b) denote the sameas the above mentioned),n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I), wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group, R² is a hydrogen atom or amethyl group, G is a hydrogen atom, a group represented by formula,

or a group represented by formula,

(wherein in formula, R^(3a) and R^(4a) denote the same as the abovementioned),n represents 0, 1 or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The pyridazinone compound represented by the formula (I-1),

(wherein in formula,R²⁻¹ represents a hydrogen atom or a C₁₋₃ alkyl group,G¹ represents a hydrogen atom, a C₁₋₃ alkylcarbonyl group optionallysubstituted by at least one halogen atom, a alkoxycarbonyl group or aC₆₋₁₀ arylcarbonyl group,Z¹⁻¹ represents a C₁₋₃ alkyl group,Z²⁻¹⁻¹ represents a C₁₋₃ alkyl group and Z²⁻¹⁻² represents a hydrogenatom or a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I-1), wherein R²⁻¹ is ahydrogen atom, a methyl group or an ethyl group, G¹ is a hydrogen atom,an acetyl group, a propionyl group, a methoxycarbonyl group, anethoxycarbonyl group or a benzoyl group,

Z¹⁻¹ is a methyl group or an ethyl group,Z²⁻¹⁻¹ is a methyl group or an ethyl group andZ²⁻¹⁻² is a hydrogen atom, a methyl group or an ethyl group).

The pyridazinone compound represented by the formula (I-2),

(wherein in formula, R²⁻² represents a hydrogen atom or a C₁₋₃ alkylgroup,G² represents a hydrogen atom, a C₁₋₃ alkylcarbonyl group optionallysubstituted by at least one halogen atom or a C₁₋₃ alkoxycarbonyl group,Z²⁻²⁻¹ represents a hydrogen atom or a C₁₋₃ alkyl group andZ²⁻²⁻² represents a hydrogen atom or a C₁₋₃ alkyl group).

The pyridazinone compound in the formula (I-2), wherein R²⁻² is ahydrogen atom, a methyl group or an ethyl group, G² is a hydrogen atom,an acetyl group, a methoxycarbonyl group or an ethoxycarbonyl group

Z²⁻²⁻¹ is a hydrogen atom, a methyl group or an ethyl group andZ²⁻²⁻² is a hydrogen atom, a methyl group or an ethyl group).

The present compounds have an excellent weed controlling activity andcan be used as an active ingredient of herbicide. Some of the presentcompounds have selectivity between crops and weeds. Examples of theweeds which the present compounds can control include following:

Weeds in fields such as Digitaria adscendens, Eleusine indica, Setariaviridis, Setaria faberi, Setaria glauca, Echinochloa crus-galli, Panicumdichotomiflorum, Brachiaria platyphylla, Sorghum halepense, Sorghumbicolor, Cynodon dactylon, Avena fatua, Lolium multiflorum, Alopecurusmyosuroides, Bromus tectorum, Bromus sterilis, Phalaris minor, Aperaspica-venti, Poa annua, Agropyron repens, Cyperus rotundus, Cyperusesculentus, Amaranthus retroflexus, Portulaca oleracea, Abutilontheophrasti, Chenopodium album, Polygonum longisetum, Solanum nigrum,Sida spinosa, Datura stramonium, Ipomoea purpurea, Xanthium strumarium,Cassia obtusifolia, Ambrosia artemisiifolia, Commelina communis, Galiumaparine, Stellaria media, Brassica spp., Matricaria chamomilla, Veronicapersica, Viola arvensis, Papaver rhoeas, Convolvulus arvensis, Erigeroncanadensis and the like;

weeds in paddy fields such as Echinochloa oryzicola, Echinochloacrus-galli, Cyperus difformis, Cyperus iria, Fimbristylis miliacea,Eleocharis acicularis, Scirpus juncoides, Scirpus wallichii, Cyperusserotinas, Eleocharis kuroguwai, Scirpus planiculmis, Scirpusnipponicus, Monochoria vaginalis, Lindernia procumbens, Dopatriumjunceum, Rotala indica, Ammannia multiflora, Elatine triandra, Ludwigiaprostrata, Sagittaria pygmaea, Alisma canaliculatum, Sagittariatrifolia, Potamogeton distinctus, Oenanthe javanica, Callitriche verna,Vandellia angustifolia, Lindernia dubia, Eclipta prostrata, Murdanniakeisak, Paspalum distichum, Leersia oryzoides and the like.

The present compound can be used for a herbicide of agricultural fieldsuch as field, paddy field, lawn, orchard and the like andnon-agricultural field. Especially, it is suitable for herbicide infield. In some cases, weeds can be controlled without damage to crops byusing the present compound in agricultural field where crops such aswheat, barley, soy bean, corn, cotton, rice and the like is growing.

When the present compound is used as an active ingredient of herbicides,the present compound are generally formulated in a dosage form suitablefor a purpose of use by dissolving or dispersing in a proper liquidcarrier or mixing with or absorbing to a proper solid carrier.Herbicides comprising the present compound are a formulated product, forexample, in a form of emulsifiable concentrate, soluble concentrate, oilsolution, aerosol, wettable powder, dust, less drifting dust, granule,micro granule, micro granule F, fine granule F, water dispersiblegranule, water soluble powder, flowable, dry flowable, jumbo tabletwhich means bagged self-diffusible powder, tablets, pastes or others.Such formulation can be further prepared as needed by adding auxiliaryagents, for instance, emulsifiers, dispersants, spreading agents,penetrating agents, wetting agents, binders, thickeners, preservatives,antioxidants, colorants or others according to a known method.

The liquid carrier used in formulation includes, for example, water,alcohols (for example, methanol, ethanol, 1-propanol, 2-propanol,ethylene glycol, etc.), ketones (for example, acetone, methyl ethylketone, etc.), ethers (for example, dioxane, tetrahydrofuran, ethyleneglycol monomethyl ether, diethylene glycol monomethyl ether, propyleneglycol monomethyl ether, etc.), aliphatic hydrocarbons (for example,hexane, octane, cyclohexane, kerosene, burning oil, machine oil, etc.),aromatic hydrocarbons (for example, benzene, toluene, xylene, solventnaphtha, methylnaphthalene, etc.), halogenated hydrocarbons (forexample, dichloromethane, chloroform, carbontetrachloride, etc.), acidamides (for example, dimethylformamide, dimethylacetamide,N-methylpyrrolidone, etc.), esters (for example, ethyl acetate, butylacetate, glyceryl fatty acid ester, etc.), nitriles (for example,acetonitrile, propionitrile, etc.) and the like. Two or more of suchliquid carriers may be mixed in a proper ratio for use.

The solid carrier used in formulation includes plant powder (forexample, soy flour, alfalfa flour, wheat flour, wood flour, etc.),mineral powder (for example, clays such as kaolin, bentonite, acid clay,clay, etc., talcs such as talc powder, pyrophillite powder, etc., silicasuch as diatomaceous earth, mica powder, etc.), alumina, sulfur powder,active charcoal, saccharides (for example, lactose, glucose, etc.),inorganic salts (for example, calcium carbonate, sodium bicarbonate,etc.), glass hollow bodies (natural vitreous materials being calcined toencapsulate air bubbles in it) and the like. Two or more of such solidcarriers may be mixed in a proper ratio for use.

The amount of the liquid carrier or solid carrier used is generally 1 to99% by weight, preferably about 10 to 99% by weight against total amountof the formulation.

Surfactants are generally used as emulsifiers, dispersants, spreadingagents, penetrating agents, wetting agents or others used informulation. Surfactants include, for example, anionic surfactants suchas alkyl sulfate ester salts, alkylarylsulfonates, dialkylsulfosuccinates, polyoxyethylene alkylaryl ether phosphate salts, ligninsulfonate, naphthalenesulfonate-formaldehyde polycondensates, etc., andnonionic surfactants such as polyoxyethylene alkyl ether,polyoxyethylene alkylaryl ether, polyoxyethylenealkyl polyoxypropyleneblock copolymer, sorbitol fatty acid ester and the like. Two or more ofsuch surfactants may be used. The amount of the surfactant used isgenerally 0.1 to 50% by weight, preferably about 0.1 to 25% by weightagainst a total amount of the formulation.

Binders and thickeners include, for example, dextrin, sodium salt ofcarboxylmethylcellulose, polycarboxylic acid type polymers,polyvinylpyrrolidone, polyvinyl alcohol, sodium lignin sulfonate,calcium lignin sulfonate, sodium polyacrylate, gum acacia, sodiumalginate, mannitol, sorbitol, bentonite type mineral matters,polyacrylic acid and derivatives thereof, white carbon, naturalsaccharide derivatives (for example, xanthan gum, guar gum, etc.) orothers.

The content ratio of the present compound in the formulation isgenerally 1 to 90% by weight in the form of the emulsifiableconcentrate, wettable powder, water dispersible granule, solubleconcentrate, water soluble powder, flowable and the like, generally 0.01to 10% by weight in the form of the oil miscible liquid, dust, lessdrifting dust and the like and generally 0.05 to 10% by weight in theform of the micro granule, micro granule F, fine granule F, granule andthe like, respectively, but the concentration may appropriately bevaried according to a purpose of use. The emulsifiable concentrate,wettable powder, water dispersible granule, soluble concentrate, watersoluble powder, flowable or others are generally properly diluted withwater or others and generally used after diluting to about 100 to100,000 times the concentration of the ingredient.

The method to apply the herbicides comprising the present compound as anactive ingredient is similar to a conventional general applicationmethod for known agricultural chemicals and includes, for example,aerial spraying, soil broadcast, foliage application or the like.

When the herbicides comprising the present compound as an activeingredient is used as the herbicide for dry or paddy field, the amountthereof may be varied with an applied area, an applied time of year, anapplication method, target weed species, cultivated crop or the like,but generally in the range of 1 to 5000 g, preferably in the range of 10to 1000 g of the present compound per one hectare of dry or paddy field.

The herbicides comprising the present compound as an active ingredientfor weed control in the dry field are generally used as a pre-emergencesoil incorporation treatment agent, pre-emergence soil treatment agentor post-emergence foliage treatment agent. Such herbicides for weedcontrol in the paddy field is generally used as a pre-emergence soiltreatment agent or both foliage and soil treatment agent.

The herbicide which comprises the present compound as an activeingredient can simultaneously be applied, if necessary, with one or morekinds of other herbicides, plant growth regulators, fungicides,insecticides, acaricides, nematocides and the like. Or it can be used incombination with one or more kinds of other herbicides, plant growthregulators, fungicides, insecticides, acaricides, nematocides and thelike.

Active ingredients of the other herbicide which can simultaneously beapplied and/or can be used in combination with the present compoundinclude, for example, as follows:

(1) herbicidal phenoxyfatty acid compounds [2,4-PA, MCP, MCPB,phenothiol, mecoprop, fluroxypyr, triclopyr, clomeprop, naproanilide andthe like],(2) herbicidal benzoic acid compounds [2,3,6-TBA, dicamba, clopyralid,picloram, aminopyralid, quinclorac, quinmerac and the like],(3) herbicidal urea compounds [diuron, linuron, chlortoluron,isoproturon, fluometuron, isouron, tebuthiuron, methabenzthiazuron,cumyluron, daimuron, methyl-daimuron and the like],(4) herbicidal triazine compounds [atrazine, ametoryn, cyanazine,simazine, propazine, simetryn, dimethametryn, prometryn, metribuzin,triaziflam and the like],(5) herbicidal bipyridinium compounds [paraquat, diquat and the like],(6) herbicidal hydroxybenzonitrile compounds [bromoxynil, ioxynil andthe like],(7) herbicidal dinitroaniline compounds [pendimethalin, prodiamine,trifluralin and the like],(8) herbicidal organophosphorus compounds [amiprofos-methyl, butamifos,bensulide, piperophos, anilofos, glyphosate, glufosinate, bialaphos andthe like],(9) herbicidal carbamate compounds [di-allate, tri-allate, EPTC,butylate, benthiocarb, esprocarb, molinate, dimepiperate, swep,chlorpropham, phenmedipham, phenisopham, pyributicarb, asulam and thelike],(10) herbicidal acid amide compounds [propanil, propyzamide,bromobutide, etobenzanid and the like],(11) herbicidal chloroacetoanilide compounds [acetochlor, alachlor,butachlor, dimethenamid, propachlor, metazachlor, metolachlor,pretilachlor, thenylchlor, pethoxamid and the like],(12) herbicidal diphenylether compounds [acifluorfen-sodium, bifenox,oxyfluorfen, lactofen, fomesafen, chlomethoxynil, aclonifen and thelike],(13) herbicidal cyclic imide compounds [ oxadiazon, cinidon-ethyl,carfentrazone-ethyl, surfentrazone, flumiclorac-pentyl, flumioxazin,pyraflufen-ethyl, oxadiargyl, pentoxazone, fluthiacet-methyl,butafenacil, benzfendizone and the like],(14) herbicidal pyrazole compounds [benzofenap, pyrazolate, pyrazoxyfen,topramezone, pyrasulfotole and the like],(15) herbicidal triketone compounds [isoxaflutole, benzobicyclon,sulcotrione, mesotrione, tembotrione, tefuryltrione and the like],(16) herbicidal aryloxyphenoxypropionate compounds[clodinafop-propargyl, cyhalofop-butyl, diclofop-methyl,fenoxaprop-ethyl, fluazifop-butyl, haloxyfop-methyl, quizalofop-ethyl,metamifop and the like],(17) herbicidal trione oxime compounds [alloxydim-sodium, sethoxydim,butroxydim, clethodim, cloproxydim, cycloxydim, tepraloxydim,tralkoxydim, profoxydim and the like],(18) herbicidal sulfonylurea compounds [chlorsulfuron,sulfometuron-methyl, metsulfuron-methyl, chlorimuron-ethyl,tribenuron-methyl, triasulfuron, bensulfuron-methyl,thifensulfuron-methyl, pyrazosulfuron-ethyl, primisulfuron-methyl,nicosulfuron, amidosulfuron, cinosulfuron, imazosulfuron, rimsulfuron,halosulfuron-methyl, prosulfuron, ethametsulfuron-methyl,triflusulfuron-methyl, flazasulfuron, cyclosulfamuron, flupyrsulfuron,sulfosulfuron, azimsulfuron, ethoxysulfuron, oxasulfuron,iodosulfuron-methyl-sodium, foramsulfuron, mesosulfuron-methyl,trifloxysulfuron, tritosulfuron, orthosulfamuron, flucetosulfuron andthe like],(19) herbicidal imidazolinone compounds [ imazamethabenz-methyl,imazamethapyr, imazamox, imazapyr, imazaquin, imazethapyr and the like],(20) herbicidal sulfonamide compounds [flumetsulam, metosulam,diclosulam, florasulam, cloransulam-methyl, penoxsulam, pyroxsulam andthe like],(21) herbicidal pyrimidinyloxybenzoate compounds [pyrithiobac-sodium,bispyribac-sodium, pyriminobac-methyl, pyribenzoxim, pyriftalid,pyrimisulfan and the like],(22) other kinds of herbicidal compounds [bentazon, bromacil, terbacil,chlorthiamid, isoxaben, dinoseb, amitrole, cinmethylin, tridiphane,dalapon, diflufenzopyr-sodium, dithiopyr, thiazopyr,flucarbazone-sodium, propoxycarbazone-sodium, mefenacet, flufenacet,fentrazamide, cafenstrole, indanofan, oxaziclomefone, benfuresate, ACN,pyridate, chloridazon, norflurazon, flurtamone, diflufenican,picolinafen, beflubutamid, clomazone, amicarbazone, pinoxaden,pyraclonil, pyroxasulfone, thiencarbazone-methyl and the like] and thelike.

Active ingredients of the plant growth regulator include, for example,hymexazol, paclobutrazol, uniconazole-P, inabenfide,prohexadione-calcium and the like.

Active ingredients of the fungicide include, for example, as follows:

(1) fungicidal polyhaloalkylthio compounds [captan and the like],(2) fungicidal organophosphorus compounds [IBP, EDDP, tolclofos-methyland the like],(3) fungicidal benzimidazole compounds [benomyl, carbendazim,thiophanate-methyl and the like],(4) fungicidal carboxyamide compounds [carboxin, mepronil, flutolanil,thifluzamid, furametpyr, boscalid, penthiopyrad and the like],(5) fungicidal dicarboxyimide compounds [procymidone, iprodione,vinclozolin and the like],(6) fungicidal acylalanine compounds [metalaxyl and the like],(7) fungicidal azole compounds [triadimefon, triadimenol, propiconazole,tebuconazole, cyproconazole, epoxiconazole, prothioconazole, ipconazole,triflumizole, prochloraz and the like],(8) fungicidal morpholine compounds [dodemorph, tridemorph,fenpropimorph and the like],(9) fungicidal strobilurin compounds [azoxystrobin, kresoxim-methyl,metominostrobin, trifloxystrobin, picoxystrobin, pyraclostrobin and thelike],(10) fungicidal antibiotics [validamycin A, blasticidin S, kasugamycin,polyoxin and the like],(11) fungicidal dithiocarbamate compounds [mancozeb, maneb and thelike],(12) other kinds of fungicidal compounds [fthalide, probenazole,isoprothiolane, tricyclazole, pyroquilon, ferimzone, acibenzolarS-methyl, carpropamid, diclocymet, fenoxanil, tiadinil, diclomezine,teclofthalam, pencycuron, oxolinic acid, TPN, triforine, fenpropidin,spiroxamine, fluazinam, iminoctadine, fenpiclonil, fludioxonil,quinoxyfen, fenhexamid, silthiofam, proquinazid, cyflufenamid, bordeauxmixture and the like] and the like.

Active ingredients of the insecticide include, for example, as follows:

(1) insecticidal organophosphorus compounds [fenthion, fenitrothion,pirimiphos-methyl, diazinon, quinalphos, isoxathion, pyridafenthion,chlorpyrifos-methyl, vamidothion, malathion, phenthoate, dimethoate,disulfoton, monocrotophos, tetrachlorvinphos, chlorfenvinphos,propaphos, acephate, trichlorphon, EPN, pyraclofos and the like],(2) insecticidal carbamate compounds [carbaryl, metolcarb, isoprocarb,BPMC, propoxur, XMC, carbofuran, carbosulfan, benfuracarb, furathiocarb,methomyl, thiodicarb and the like],(3) insecticidal synthetic pyrethroid compounds [tefluthrin, bifenthrin,cycloprothrin, ethofenprox and the like],(4) insecticidal nereistoxin-based compounds [cartap, bensultap,thiocyclam and the like],(5) insecticidal neonicotinoid compounds [imidacloprid, nitenpyram,acetamiprid, thiamethoxam, thiacloprid, dinotefuran, clothianidin andthe like],(6) insecticidal benzoylphenylurea compounds [chlorfluazuron,flufenoxuron, hexaflumuron, lufenuron, novaluron and the like],(7) insecticidal macrolide compounds [emamectin, spinosad and the like],(8) other kinds of insecticidal compounds [buprofezin, tebufenozide,fipronil, ethiprole, pymetrozine, diafenthiuron, indoxacarb,tolfenpyrad, pyridalyl, flonicamid, flubendiamide and the like] and thelike.

Active ingredients of the acaricide include, for example, hexythiazox,pyridaben, fenpyroximate, tebufenpyrad, chlorfenapyr, etoxazole,pyrimidifen, acequinocyl, bifenazate, spirodiclofen and the like.

Active ingredients of the nematocide include, for example, fosthiazate,cadusafos and the like.

The herbicide which contains the present compound as an activeingredient may, if necessary, be further mixed with a safener (forexample, furilazole, dichlormid, benoxacor, allidochlor,isoxadifen-ethyl, fenchlorazole-ethyl, mefenpyr-diethyl,cloquintocet-mexyl, fenclorim, cyprosulfamide, cyometrinil, oxabetrinil,fluxofenim, flurazole, 1,8-naphthalic anhydride and the like), coloringagent, fertilizer (for example, urea and the like) and the like.

The present compound may be used as an active ingredient of herbicidesfor croplands such as a field, a rice paddy, a lawn, an orchard, ornon-croplands. The present compound may control weeds without causingany crop injury to “crops” in a place cultivating the “crops” listedbelow.

“Crops”

Corn, rice, wheat, barley, rye, oats, sorghum, cotton, soybean, peanut,common buckwheat, sugar beet, rape, sunflower, sugar cane, tobacco andthe like;

Solanaceae vegetables (eggplant, tomato, green pepper, red pepper,potato and the like), Cucurbitaceous vegetables (cucumber, pumpkin,zucchini, watermelon, melon and the like), Brassicaceae vegetables(Japanese radish, turnip, horseradish, kohlrabi, Chinese cabbage,cabbage, leaf mustard, broccoli, cauliflower and the like), Compositaevegetables (burdock, garland chrysanthemum, artichoke, lettuce and thelike), Liliaceae vegetables (leek, onion, garlic, asparagus and thelike), Umbelliferae vegetables (carrot, parsley, celery, wild parsnipand the like), Chenopodiaceae vegetables (spinach, Swiss chard and thelike), Labiatae vegetables (perilla, mint, basil and the like),strawberry, sweet potato, yam, taro and the like;

ornamental flowers;

houseplants;

pomaceous fruits (apple, pear, Japanese pear, Chinese quince, quince andthe like), stone fruits (peach, plum, nectarine, Japanese plum, mahalebcherry, apricot, prune and the like), citrus (tangerine, orange, lemon,lime, grapefruit and the like), nuts (chestnut, walnut, hazel, almond,pistachio, cashew nut, macadamia nut and the like), sap fruits(blueberry, cranberry, blackberry, raspberry and the like), grape,persimmon, olive, loquat, banana, coffee, date palm, coconut palm andthe like; and

tea plant, mulberry, flowering plants, roadside trees (ash plant, birch,American dogwood, eucalyptus, ginkgo, lilac, maple, willow oak, poplar,cercis, liquidambar, plane tree, zelkova, Thuja standishii, Abies,hemlock spruce, needle juniper, pine, Norway spruce, yew) and the like.

Crops being conferred resistance to herbicides by classic breedingtechnique, gene recombination technology or the like are included insuch “crops”. There is no crop injury to the crops, to which resistanceto herbicides was given, when herbicides such as HPPD inhibitors such asisoxaflutole; ALS inhibitors such as imazethapyr, thifensulfuron-methyl;EPSP synthase inhibitors; glutamine synthetase inhibitors; acetyl CoAcarboxylase inhibitors; or bromoxynil and the like; are applied.

The crops to which herbicidal resistance is given by classic breedingtechnique include, for example, Clearfield (registered trademark) canolawith resistance to imidazolinone herbicides, STS soy bean withresistance to sulfonylurea herbicides, SR corn with resistance to acetylCoA carboxylase inhibitors. The crops, to which the resistance to acetylCoA carboxylase inhibitors is given, are described in, for example,Proc. Natl. Acad. Sci. USA, vol. 87, pp. 7175 (1990).

In addition, mutant acetyl CoA carboxylase conferring resistance toacetyl CoA carboxylase inhibitors is described, for example, in WeedScience vol. 53, pp. 728-746 (2005). Resistance to acetyl CoAcarboxylase inhibitors can be conferred to the crops when the genecoding this mutant acetyl CoA carboxylase is introduced into the cropsby gene recombination technology, or when mutations related to acetylCoA carboxylase inhibitor-resistance is introduced into the gene codingacetyl CoA carboxylase.

The “crops” to which herbicidal resistance is conferred by generecombination technology are known (for example, corn varieties to whichresistance to glyphosate or glufosinate is added). Such corn varietiesare commercially available as a product name of Roundup Ready(registered trademark) or Liberty Link (registered trademark).

The “crops” include crops to which ability to produce insecticidaltoxins is given by gene recombination technology.

Such insecticidal toxins include, for example, insecticidal proteinsproduced from Bacillus cereus or Bacillus popilliae; δ-endotoxins suchas Cry1Ab, Cry1Ac, Cry1F, Cry1Fa2, Cry2Ab, Cry3A, Cry3Bb1 and Cry9Cproduced from Bacillus thuringiensis; insecticidal proteins such asVIP1, VIP2, VIP3 and VIP3A; insecticidal proteins produced fromnematode; toxins produced by animals such as a scorpion toxin, a spidertoxin, a bee toxin and an insect specific nervous system toxin;Filamentous fungus toxins; Plant lectins; Agglutinins; proteaseinhibitors such as trypsin inhibitors, serine protease inhibitors,patatin, cystatin and papain inhibitors; ribosome inactivation proteins(RIP) such as ricins, corn-RIP, abrins, saporins, bryodin; steroidmetabolism enzymes such as 3-hydroxysteroid oxidase,ecdysteroid-UDP-glucosyltransferase, cholesterol oxidase; ecdysoneinhibitors; HMG-CoA reductase; ion channel inhibitors such as sodiumchannel or calcium channel inhibitor; Juvenile hormone esterase;diuretic hormone receptors; stilbene synthase; bibenzyl synthase;chitinase; and glucanases.

The insecticidal toxins include hybrid proteins of said insecticidalproteins, insecticidal proteins in which a part of amino acids composingthe proteins is deleted or substituted. Hybrid proteins are created byputting different domains of these insecticidal proteins together bygene recombination technology. For example, Cry1Ab, in which a part ofamino acid is deleted, is known as the above insecticidal protein inwhich a part of amino acids composing the protein is deleted.

For example, insecticidal toxins and the “crops” being given an abilityto produce insecticidal toxins by gene recombination technology aredescribed in EP-A-0 374 753, WO 93/07,278, WO 95/34,656, EP-A-0 427 529,EP-A-451 878 and WO 03/052,073.

For example, the “crops” being given an ability to produce insecticidaltoxins by gene recombination technology have resistance to attack fromColeopteran pests, Dipteran pests and/or Lepidopteran pests.

Examples of commercially available “crops” being given an ability toproduce insecticidal toxins by gene recombination technology includeYieldGard (registered trademark) (corn variety expressing Cry1Ab toxin),YieldGard Rootworm (registered trademark) (corn variety expressingCry3Bb1 toxin), YieldGard Plus (registered trademark) (corn varietyexpressing Cry1Ab and Cry3Bb1 toxins), Herculex I (registered trademark)(corn variety expressing Cry1Fa2 toxin and phosphinothricinN-acetyltransferase (PAT) to confer resistance to glufosinate),NuCOTN33B (registered trademark) (cotton variety expressing Cry1Actoxin), Bollgard I (registered trademark) (cotton variety expressingCry1Ac toxin), Bollgard II (registered trademark) (cotton varietyexpressing Cry1Ac and Cry2Ab toxins), VIPCOT (registered trademark)(cotton variety expressing VIP toxin), NewLeaf (registered trademark)(potato variety expressing Cry3A toxin), NatureGard (registeredtrademark) Agrisure (registered trademark) GT Advantage (GA21 glyphosateresistance trait), Agrisure (registered trademark) CB Advantage (Bt11corn borer (CB) trait) and Protecta (registered trademark).

The “crops” also include crops being given an ability to produceanti-pathogen substances by gene recombination technology.

Anti-pathogen substances include, for example, PR proteins (PRPs,described in EP-A-0 392 225); ion channel inhibitors such as sodiumchannel inhibitors, calcium channel inhibitors (KP1, KP4 and KP6 toxinsand the like produced by virus are known); stilbene synthase; bibenzylsynthase; chitinase; glucanase; microorganism-producing substances suchas peptide antibiotics, antibiotics having a heterocycle; and proteinfactors relating to resistance against plant pathogens (described in WO03/000,906) and the like.

The crops being given an ability to produce an anti-pathogen substanceby gene recombination technology are described, for example, in EP-A-0392 225, WO 95/33, 818 and EP-A-0 353 191.

When the present compound is mixed with flumioxazin, the mixing ratio ispreferably 0.1 to 10 by weight of flumioxazin based on 1 by weight ofthe present compound. The composition comprising the present compoundand flumioxazin can be used for soil treatment or foliage treatment. Thecomposition comprising the present compound and flumioxazin may controlweeds without causing any crop injury in a place cultivating corn, rice,wheat, barley, rye, oats, sorghum, cotton, soybean, peanut, sugar beet,rape, sunflower, sugarcane and the like. And the composition comprisingthe present compound and flumioxazin may be used for croplands such as alawn, an orchard, or non-croplands.

When the present compound is mixed with glyphosate, the mixing ratio ispreferably 1 to 100 by weight of glyphosate based on 1 by weight of thepresent compound. The composition comprising the present compound andglyphosate can be used for foliage treatment. The composition comprisingthe present compound and glyphosate may control weeds without giving anycrop injury in a place cultivating corn, rice, wheat, barley, rye, oats,sorghum, cotton, soy bean, peanut, sugar beet, rape, sunflower,sugarcane and the like. And the composition comprising the presentcompound and glyphosate may be used for croplands such as a lawn, anorchard, or non-croplands.

The present compound can be produced, for example, by followingpreparation methods.

Preparation Method 1

Among the present compound, the compound represented by the formula(I-a), in which G is a hydrogen atom can be produced by the reaction ofthe compound represented by the formula (II) with a metal hydroxide,

(wherein in formula, R⁷ represents a C₁₋₆ alkyl group (for example, amethyl group, an ethyl group, etc.) and R¹, R², Z¹, Z² and n denote thesame as the above mentioned).

The reaction is generally carried out in a solvent. The solvent used inthe reaction includes, for example, water, ethers such astetrahydrofuran, dioxane or a mixed solvent thereof.

The metal hydroxide used in the reaction includes, for example, ahydroxide of an alkali metal such as sodium hydroxide, potassiumhydroxide and the like. The amount of the metal hydroxide used in thereaction is generally 1 to 120 mole equivalents, preferably 1 to 40 moleequivalents to the compound represented by the formula (II).

The reaction temperature is generally in the range of room temperatureto boiling point of the solvent, preferably at a boiling point of thesolvent. The reaction may be carried out by heating in a sealed tube ora high pressure resistant closed vessel. The reaction time is generallyin the range from 5 minutes to a few weeks.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or the like after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (I-a) may be isolated, for example, by the followingoperation: addition of an acid to the reaction mixture, to which wateris added to mix, followed by extraction with an organic solvent to forman organic layer, which is dried and concentrated.

Preparation Method 2

Among the present compound, the compounds represented by the formula(I-b), in which G is a group except a hydrogen atom can be produced fromthe compound represented by the formula (I-a) and the compoundrepresented by the formula (III),

(wherein in formula, G³ among G defined represents a group except ahydrogen atom, X represents a halogen atom (for example, a chlorineatom, a bromine atom, an iodine atom, etc.) or a group represented bythe formula OG³ and R¹, R², Z¹, Z² and n denote the same as the abovementioned).

The reaction may be carried out in a solvent. The solvent used in thereaction includes, for example, aromatic hydrocarbons such as benzene,toluene, etc., ethers such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran, dimethoxyethane, etc., halogenated hydrocarbons such asdichloromethane, chloroform, 1,2-dichloroethane, etc., amides such asdimethylformamide, dimethylacetamide, etc., sulfoxides such asdimethylsulfoxide, etc., sulfones such as sulforane, etc. or a mixedsolvent thereof.

The compound represented by the formula (III) used in the reactionincludes, for example, carboxylic acid halides such as acetyl chloride,propionyl chloride, isobutyryl chloride, pivaloyl chloride, benzoylchloride, cyclohexanecarbonyl chloride, etc., carboxylic acid anhydridessuch as acetic anhydride, trifluoroacetic anhydride, etc., carbonatehalf ester halides such as methyl chloroformate, ethyl chloroformate,phenyl chloroformate, etc., carbamoyl halides such as dimethylcarbamoylchloride, etc., sulfonyl halides such as methanesulfonyl chloride,p-toluenesulfonyl chloride, etc., sulfonic acid anhydrides such asmethanesulfonic anhydride, trifluoromethanesulfonic anhydride, etc., orhalogenated phosphate esters such as dimethyl chlorophosphate, etc. Theamount of the compound represented by the formula (III) used in thereaction is generally one mole equivalent or more, preferably 1 to 3mole equivalents to the compound represented by the formula (I-a).

The reaction is generally carried out in the presence of a base. Thebase used in the reaction includes, for example, organic bases such astriethylamine, tripropylamine, pyridine, dimethylaminopyridine,1,8-diazabicyclo[5.4.0]-7-undecene, etc., and inorganic bases such assodium hydroxide, potassium hydroxide, calcium hydroxide, sodiumcarbonate, potassium carbonate, sodium hydrogen carbonate, calciumcarbonate, sodium hydride, etc. The amount of the base used in thereaction is generally 0.5 to 10 mole equivalents, preferably 1 to 5 moleequivalents to the compound represented by the formula (I-a).

The reaction temperature is generally at −30 to 180° C., preferably at−10 to 50° C. The reaction time is generally from 10 minutes to 30hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or the like after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (I-b) may be isolated, for example, by the followingoperation: mixing the reaction mixture with water followed by extractionwith an organic solvent to form an organic layer, which is dried andconcentrated.

The compound represented by the formula (III) is a known compound or maybe produced from a known compound.

Preparation Method 3

Among the present compound, the compound represented by the formula(I-a), in which G is a hydrogen atom can also be produced by thefollowing preparation method. The compound represented by the formula(I-a) can be produced by the reaction of the compound represented by theformula (VI) with a base,

(wherein in formula, R⁹ represents a C₁₋₆ alkyl group (for example, amethyl group, an ethyl group, etc.) and R¹, R², Z¹, Z² and n denote thesame as the above mentioned).

The reaction is generally carried out in a solvent. The solvent used inthe reaction includes, for example, aromatic hydrocarbons such asbenzene, toluene, xylene, etc., ethers such as diethyl ether,diisopropyl ether, dioxane, tetrahydrofuran, dimethoxyethane, etc.,halogenated hydrocarbons such as dichloromethane, chloroform,1,2-dichloroethane, etc., amides such as dimethylformamide,dimethylacetamide, etc., sulfones such as sulforane, etc., or a mixedsolvent thereof.

The base used in the reaction includes, for example, metal alkoxidessuch as potassium tert-butoxide, etc., alkali metal hydrides such assodium hydride, etc., and organic bases such as triethylamine,tributylamine, N,N-diisopropylethylamine, etc. The amount of the baseused in the reaction is generally 1 to 10 mole equivalents, preferably 2to 5 mole equivalents to the compound represented by the formula (VI).

The reaction temperature is generally at −60 to 180° C., preferably at−10 to 100° C. The reaction time is generally from 10 minutes to 30hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or the like after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (I-a) may be isolated, for example, by the followingoperation: addition of an acid to the reaction mixture, to which wateris added to mix, followed by extraction with an organic solvent to forman organic layer, which is dried and concentrated.

Reference Preparation Method 1

The compound represented by the formula (II) can be produced, forexample, by the following preparation method,

(wherein in formula, X¹ represents a leaving group (for example, ahalogen atom such as a chlorine atom, a bromine atom, an iodine atom,etc.), X² represents a halogen atom (for example, a chlorine atom, abromine atom, an iodine atom, etc.), R⁸ represents a C₁₋₆ alkyl group(for example, a methyl group, a butyl group, etc.) and R¹, R², R⁷, Z¹,Z² and n denote the same as the above mentioned).

The compound represented by the formula (II) can be produced by acoupling reaction of the compound represented by the formula (IV) withan organometallic reagent represented by the formulas (V-a), (V-b) or(V-c) (generally one mole equivalent or more, preferably 1 to 3 moleequivalents to the compound represented by the formula (IV)).

When the compound represented by the formula (V-a) is used, saidcoupling reaction is carried out in a solvent. The solvent used in thereaction includes, for example, aromatic hydrocarbons such as benzene,toluene, etc., alcohols such as methanol, ethanol, propanol, etc.,ethers such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran, dimethoxyethane, etc., ketones such as acetone, methylethyl ketone, etc., amides such as dimethylformamide, dimethylacetamide,etc., sulfoxides such as dimethylsulfoxide, etc., sulfones such assulfolane, etc., water or a mixed solvent thereof.

When the compound represented by the formula (V-a) is used, saidcoupling reaction is carried out in the presence of a base. The baseused in the reaction includes, for example, organic bases such astriethylamine, tripropylamine, pyridine, dimethylaniline,dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]-7-undecene, etc., andinorganic bases such as sodium hydroxide, potassium hydroxide, calciumhydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, calcium carbonate, cesium carbonate, potassium phosphate,etc. The amount of the base used in the reaction is generally 0.5 to 10mole equivalents, preferably 1 to 5 mole equivalents to the compoundrepresented by the formula (IV).

Furthermore, when the compound represented by the formula (V-a) is used,said coupling reaction is carried out in the presence of a catalyst. Thecatalyst used in the reaction includes, for example, a palladiumcatalyst such as tetrakis(triphenylphosphine)palladium,dichlorobis(triphenylphosphine)palladium, etc. The amount of thecatalyst used in the reaction is generally 0.001 to 0.5 mole equivalent,preferably 0.01 to 0.2 mole equivalent to the compound represented bythe formula (IV). When the compound represented by the formula (V-a) isused, a quaternary ammonium salt is preferably added in said couplingreaction. The quaternary ammonium salt used includes, for example,tetrabutylammonium bromide, etc.

When the compound represented by the formula (V-a) is used, a reactiontemperature of said coupling reaction is generally at 20 to 180° C.,preferably at 60 to 150° C. The reaction time is generally from 30minutes to 100 hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or the like after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (II) may be isolated, for example, by the followingoperation: mixing the reaction mixture with water, followed byextraction with an organic solvent to form an organic layer, which isdried and concentrated.

When the compound represented by the formula (V-b) is used, saidcoupling reaction is carried out in a solvent. The solvent used in thereaction includes, for example, aromatic hydrocarbons such as benzene,toluene, etc., ethers such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran, dimethoxyethane, etc., or a mixed solvent thereof.

When the compound represented by the formula (V-b) is used, saidcoupling reaction is carried out in the presence of a catalyst. Thecatalyst used in the reaction includes, for example, a nickel catalystsuch as dichlorobis(1,3-diphenylphosphino)propanenickel,dichlorobis(triphenylphosphine)nickel, etc., and a palladium catalystsuch as tetrakis(triphenylphosphine)palladium,dichlorobis(triphenylphosphine)palladium, etc. The amount of thecatalyst used in the reaction is generally 0.001 to 0.5 mole equivalent,preferably 0.01 to 0.2 mole equivalent to the compound represented bythe formula (IV).

When the compound represented by the formula (V-b) is used, the reactiontemperature of said coupling reaction is generally at −80 to 180° C.,preferably at −30 to 150° C. The reaction time is generally from 30minutes to 100 hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or others after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (II) may be isolated, for example, by the followingoperation: mixing the reaction mixture with water, followed byextraction with an organic solvent to form an organic layer, which isdried and concentrated.

When the compound represented by the formula (V-c) is used, saidcoupling reaction is carried out in a solvent. The solvent used in thereaction includes, for example, aromatic hydrocarbons such as benzene,toluene, etc., ethers such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran, dimethoxyethane, etc., halogenated hydrocarbons such aschloroform, 1,2-dichloroethane, etc., amides such as dimethylformamide,dimethylacetamide, etc., or a mixed solvent thereof.

When the compound represented by the formula (V-c) is used, saidcoupling reaction is carried out in the presence of a catalyst. Thecatalyst used in the reaction includes, for example, a palladiumcatalyst such as tetrakis(triphenylphosphine)palladium,dichlorobis(triphenylphosphine)palladium, etc. The amount of thecatalyst used in the reaction is generally 0.001 to 0.5 mole equivalent,preferably 0.01 to 0.2 mole equivalent to the compound represented bythe formula (IV).

When the compound represented by the formula (V-c) is used, the reactiontemperature of said coupling reaction is generally at −80 to 180° C.,preferably at −30 to 150° C. The reaction time is generally from 30minutes to 100 hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or others after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (II) may be isolated, for example, by the followingoperation: mixing the reaction mixture with water, followed byextraction with an organic solvent to form an organic layer, which isdried and concentrated.

The compound represented by the formula (II) can be produced, forexample, by a method in accordance with the one described in Tetrahedronvol. 57, pp 1323-1330 (2001), etc.

Organometallic reagents represented by the formulas (V-a), (V-b) and(V-c) are known compounds or can be produced by methods in accordancewith known methods using known compounds.

The compound represented by the formula (IV) is a known compound or canbe produced using known compounds. The compound can be produced, forexample, by a method described in J. Heterocycl. Chem., vol. 33, pp1579-1582 (1996) and the like, or a method in accordance with the onethereof.

Reference Preparation Method 2

The compound represented by the formula (VI) can be produced, forexample, by a following preparation method,

(wherein in formula, X³ represents a halogen atom (for example, achlorine atom, a bromine atom, an iodine atom, etc.) and R¹, R², R⁹, Z¹,Z² and n denote the same as the above mentioned).

The reaction is generally carried out in a solvent. The solvent used inthe reaction includes, for example, nitriles such as acetonitrile, etc.,ketones such as acetone, etc., aromatic hydrocarbons such as benzene,toluene, etc., ethers such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran, dimethoxyethane, etc., halogenated hydrocarbons such asdichloromethane, chloroform, 1,2-dichloroethane, etc., amides such asdimethylformamide, dimethylacetamide, etc., sulfones such as sulfolane,etc., or a mixed solvent thereof.

The reaction of the compound represented by the formula (VII) with thecompound represented by the formula (VIII) is generally carried out inthe presence of a base. The base used in the reaction includes, forexample, organic bases such as triethylamine, tripropylamine, pyridine,dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]-7-undecene,1,4-diazabicyclo[2.2.2]octane, etc., and inorganic bases such as sodiumhydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate,potassium carbonate, sodium hydrogen carbonate, calcium carbonate,sodium hydride, etc.

The amount of the compound represented by the formula (VIII) used in thereaction is generally 1 mole equivalent or more, preferably 1 to 3 moleequivalents to the compound represented by the formula (VII). The amountof a base used in the reaction is generally 0.5 to 10 mole equivalents,preferably 1 to 5 mole equivalents to the compound represented by theformula (VII).

The reaction temperature is generally at −30 to 180° C., preferably at−10 to 50° C. The reaction time is generally from 10 minutes to 30hours.

The completion of the reaction may be confirmed with use of ananalytical means such as thin layer chromatography, high performanceliquid chromatography or the like after sampling a part of the reactionmixture. After the completion of the reaction, the compound representedby the formula (VI) may be isolated, for example, by the followingoperation: mixing the reaction mixture with water, followed byextraction with an organic solvent to form an organic layer, which isdried and concentrated.

The compound represented by the formula (VII) can be produced by thereaction of the compound represented by the formula (IX)

(wherein in formula, Z¹, Z² and n denote the same as the abovementioned)with a halogenation reagent (for example, thionyl chloride, thionylbromide, phosphorous oxychloride, oxalyl chloride, etc.).

The compound represented by the formula (IX) is a known compound or canbe produced from known compounds. The compound can be produced, forexample, according to methods described in Organic Syntheses CollectiveVolume 3, pp 557-560 (1955), J. Am. Chem. Soc. Vol. 63, pp 2643-2644(1941) and WO 2006/056282, etc., and methods similar to them. Thecompound represented by the formula (IX) includes, for example,2,4,6-trimethylphenyl acetic acid, 2,4,6-triethylphenylacetic acid,2,6-diethyl-4-methylphenylacetic acid, 2-ethylphenylacetic2-ethyl-4,6-dimethylphenylacetic acid, 2,4-diethylphenylacetic acid,2,6-diethylphenylacetic acid, 2,6-diethyl-6-methylphenylacetic acid,etc.

The compound represented by the formula (VIII) is a known compound orcan be produced from known compounds.

Each compound produced by above mentioned Preparation method 1 to 3 orReference preparation method 1 to 2 may be isolated and/or purified byknown procedures, for example, concentration, concentration underreduced pressure, extraction, transference dissolution, crystallization,re-crystallization, chromatography and the like.

Next, specific examples of the present compound are shown below.

(1) The pyridazinone compound wherein Ar is a 2-ethylphenyl group, and Gis a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(2) The pyridazinone compound wherein Ar is a 2-propylphenyl group, andG is a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(3) The pyridazinone compound wherein Ar is a 2,4-dimethylphenyl group,and G is a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(4) The pyridazinone compound wherein Ar is a 2,6-dimethylphenyl group,and G is a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(5) The pyridazinone compound wherein Ar is a 2-ethyl-4-methylphenylgroup, and G is a hydrogen atom, an acetyl group, a trifluoroacetylgroup, a propionyl group, a butyryl group, an isobutyryl group, anisovaleryl group, a pivaloyl group, a cyclohexylcarbonyl group, abenzoyl group, a benzylcarbonyl group, a methoxycarbonyl group, anethoxycarbonyl group, a phenoxycarbonyl group, a dimethylaminocarbonylgroup, a methanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(6) The pyridazinone compound wherein Ar is a 2-ethyl-6-methylphenylgroup, and G is a hydrogen atom, an acetyl group, a trifluoroacetylgroup, a propionyl group, a butyryl group, an isobutyryl group, anisovaleryl group, a pivaloyl group, a cyclohexylcarbonyl group, abenzoyl group, a benzylcarbonyl group, a methoxycarbonyl group, anethoxycarbonyl group, a phenoxycarbonyl group, a dimethylaminocarbonylgroup, a methanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(7) The pyridazinone compound wherein Ar is a 2,6-diethylphenyl group,and G is a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(8) The pyridazinone compound wherein Ar is a 2,4,6-trimethylphenylgroup, and G is a hydrogen atom, an acetyl group, a trifluoroacetylgroup, a propionyl group, a butyryl group, an isobutyryl group, anisovaleryl group, a pivaloyl group, a cyclohexylcarbonyl group, abenzoyl group, a benzylcarbonyl group, a methoxycarbonyl group, anethoxycarbonyl group, a phenoxycarbonyl group, a dimethylaminocarbonylgroup, a methanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(9) The pyridazinone compound wherein Ar is a 2-ethyl-4,6-dimethylphenylgroup, and G is a hydrogen atom, an acetyl group, a trifluoroacetylgroup, a propionyl group, a butyryl group, an isobutyryl group, anisovaleryl group, a pivaloyl group, a cyclohexylcarbonyl group, abenzoyl group, a benzylcarbonyl group, a methoxycarbonyl group, anethoxycarbonyl group, a phenoxycarbonyl group, a dimethylaminocarbonylgroup, a methanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(10) The pyridazinone compound wherein Ar is a2,6-diethyl-4-methylphenyl group, and G is a hydrogen atom, an acetylgroup, a trifluoroacetyl group, a propionyl group, a butyryl group, anisobutyryl group, an isovaleryl group, a pivaloyl group, acyclohexylcarbonyl group, a benzoyl group, a benzylcarbonyl group, amethoxycarbonyl group, an ethoxycarbonyl group, a phenoxycarbonyl group,a dimethylaminocarbonyl group, a methanesulfonyl group, atrifluoromethanesulfonyl group, a benzenesulfonyl group or ap-toluenesulfonyl group in any of the formula (I¹) to (I³⁰).(11) The pyridazinone compound wherein Ar is a 2,4,6-triethylphenylgroup, and G is a hydrogen atom, an acetyl group, a trifluoroacetylgroup, a propionyl group, a butyryl group, an isobutyryl group, anisovaleryl group, a pivaloyl group, a cyclohexylcarbonyl group, abenzoyl group, a benzylcarbonyl group, a methoxycarbonyl group, anethoxycarbonyl group, a phenoxycarbonyl group, a dimethylaminocarbonylgroup, a methanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(12) The pyridazinone compound wherein Ar is a 2,4-diethylphenyl group,and G is a hydrogen atom, an acetyl group, a trifluoroacetyl group, apropionyl group, a butyryl group, an isobutyryl group, an isovalerylgroup, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, abenzylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group,a phenoxycarbonyl group, a dimethylaminocarbonyl group, amethanesulfonyl group, a trifluoromethanesulfonyl group, abenzenesulfonyl group or a p-toluenesulfonyl group in any of the formula(I¹) to (I³⁰).(13) The pyridazinone compound wherein Ar is a2,4-diethyl-6-methylphenyl group, and G is a hydrogen atom, an acetylgroup, a trifluoroacetyl group, a propionyl group, a butyryl group, anisobutyryl group, an isovaleryl group, a pivaloyl group, acyclohexylcarbonyl group, a benzoyl group, a benzylcarbonyl group, amethoxycarbonyl group, an ethoxycarbonyl group, a phenoxycarbonyl group,a dimethylaminocarbonyl group, a methanesulfonyl group, atrifluoromethanesulfonyl group, a benzenesulfonyl group or ap-toluenesulfonyl group in any of the formula (I¹) to (I³⁰).

The embodiments of the compound represented by the formula (II) include,for example, the following embodiments among the above defined thecompound represented by the formula (II).

The compound in the formula (II), wherein n is an integer of 1 or more.

The compound in the formula (II), wherein n is 0 and Z¹ is a C₂₋₆ alkylgroup.

The compound in the formula (II), wherein n is 1 or 2 and Z² is (a)substituent (s) on 4- and/or 6-position of the benzene ring.

The compound in the formula (II), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group.

The compound in the formula (II), wherein R² is a hydrogen atom or aC₁₋₃ alkyl group.

The compound in the formula (II), wherein R² is a hydrogen atom or amethyl group.

The compound in the formula (II), wherein Z¹ is a C₁₋₃ alkyl group andZ² is a C₁₋₃ alkyl group.

The compound in the formula (II), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a methylgroup.

The compound in the formula (II), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a C₁₋₃alkyl group,

n represents 0, 1, or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The compound in the formula (II), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a methylgroup,

n represents 0, 1, or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The embodiments of the compound represented by the formula (VI) include,for example, the following embodiments among the above defined thecompound represented by the formula (VI).

The compound in the formula (VI), wherein n is an integer of 1 or more.

The compound in the formula (VI), wherein n is 0 and Z¹ is a C₂₋₆ alkylgroup.

The compound in the formula (VI), wherein n is 1 or 2 and Z² is (a)substituent (s) on 4- and/or 6-position of the benzene ring.

The compound in the formula (VI), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group.

The compound in the formula (VI), wherein R² is a C₁₋₆ alkyl group.

The compound in the formula (VI), wherein R² is a hydrogen atom or aC₁₋₃ alkyl group.

The compound in the formula (VI), wherein R² is a C₁₋₃ alkyl group.

The compound in the formula (VI), wherein R² is a hydrogen atom or amethyl group.

The compound in the formula (VI), wherein R² is a methyl group.

The compound in the formula (VI), wherein Z¹ is a C₁₋₃ alkyl group andZ² is a C₁₋₃ alkyl group.

The compound in the formula (VI), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a methylgroup.

The compound in the formula (VI), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a C₁₋₃alkyl group,

n represents 0, 1, or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The compound in the formula (VI), wherein R¹ is a C₁₋₃ alkyl group or a(C₁₋₃ alkyloxy) C₁₋₃ alkyl group and R² is a hydrogen atom or a methylgroup,

n represents 0, 1, or 2 and each of Z² may be same or different when nrepresents 2,and when n represents 1 or 2, Z² is (a) substituent (s) on 4- and/or6-position of a benzene ring,Z¹ is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group) andZ² is a C₁₋₆ alkyl group (preferably a C₁₋₃ alkyl group).

The present invention will be further illustrated by the followingExamples, Reference examples, Formulation examples and Test examples;however the present invention is not limited to these examples.

In the Examples and Reference examples, room temperature means usually10 to 30° C. ¹H-NMR means proton nuclear magnetic resonance. It ismeasured with tetramethyl silane as internal standard, and chemicalshift (6) is shown by ppm.

The abbreviations used in the Examples and Reference examples have thefollowing meanings:

CDCl₃: Chloroform-d, s: singlet, d: doublet, t: triplet, q: quartet, dt:doublet triplet, dq: doublet quartet, m: multiplet, br.: broad, J:coupling constant, Me: methyl group, Et: ethyl group, Pr: propyl group,i-Pr: isopropyl group, t-Bu: tert-butyl group, c-Hex: cyclohexyl groupand Ph: phenyl group.

EXAMPLE 1 4-(2-Ethylphenyl)-5-hydroxy-2-methyl-3(2H)-pyridazinone(Compound I-a-1)

After 50 mL of water, 4.657 g of potassium hydroxide (content, 85%) and5 mL of 1,4-dioxane were added to 3.193 g of4-(2-ethylphenyl)-5-methoxy-2-methyl-3(2H)-pyridazinone (Compound II-1),the mixture was stirred and heated under reflux for 36 hours. Aftercooling, concentrated hydrochloric acid was added to the reactionmixture to acidify, to which 10 ml of water and 100 ml of ethyl acetatewere added. The resulting mixture was filtered to remove insolublesubstances and the filtrate was separate to two phase. The organic layerwas washed with water and then a saturated sodium chloride aqueoussolution and dried over anhydrous magnesium sulfate, and the solvent wasdistilled off. The solid obtained was washed with a mixed solvent ofethyl acetate and hexane (1:2) to yield 2.050 g of the title compound ascolorless crystals.

The present compound which was produced according to Example 1 will beshown in Table 1.

The compound represented by the formula (I-a):

TABLE 1 Compound R¹ R² Z¹ (Z²)_(n) m.p./° C. I-a-1 Me H Et — 218-220I-a-2 Et H Et — 190-192 I-a-3 i-Pr H Et — 226-227 I-a-4 MeOCH₂CH₂ H Et —137-139 I-a-5 Me H Pr — 210-211 I-a-6 Me H Me 6-Me 267-271 I-a-7 Me H Et6-Me 239-242 I-a-8 Me H Et 6-Et 247-249 I-a-9 Me H Me 4-Me 219-220I-a-10 Me H Me 4-Me, 6-Me 272-275 I-a-11 Et H Me 4-Me, 6-Me >300 I-a-12Me H Et 4-Me, 6-Et 254-255

EXAMPLE 24-(2,6-Diethyl-4-methylphenyl)-5-hydroxy-2,6-dimethyl-3(2H)-pyridazinone(Compound I-a-14)

Under a nitrogen atmosphere, 13 mL of a tetrahydrofuran solution ofpotassium tert-butoxide (1 mol/L) was stirred at room temperature, towhich a solution of 1.9 g of ethyl2-[2-(2,6-diethyl-4-methylphenylacetyl)-2-methylhydrazono]propanoate(Compound VI-2) in 55 mL of toluene was added dropwise over about 1hour. The mixture was further stirred at room temperature for 30minutes. Then, the reaction mixture was concentrated under reducedpressure. To the residue obtained was added 30 mL of ice-water, whichwas extracted with tert-butyl methyl ether (20 mL×2). To the aqueouslayer was then added 1.6 g of 35% hydrochloric acid, which was extractedwith ethyl acetate (20 mL×3). The ethyl acetate extracts were combined,washed with saturated sodium chloride aqueous solution (20 mL×2), driedover anhydrous magnesium sulfate and concentrated under reducedpressure. The residue obtained was subjected to a silica gel columnchromatography (ethyl acetate:hexane=1:3 as eluent) to yield 0.76 g of asolid. The solid was washed with cold hexane and air-dried to yield 0.59g of the title compound as white powder.

The present compound which was produced according to Example 2 will beshown in Table 2.

The compound represented by the formula (I-a):

TABLE 2 Compound R¹ R² Z¹ (Z²)_(n) m.p./° C. I-a-13 Me Me Me 4-Me, 6-Me199-201 I-a-14 Me Me Et 4-Me, 6-Et 205-206 I-a-15 Me Me Et — 171-172I-a-16 Me Me Et 4-Me 187-188 I-a-17 Me Me Et 4-Et, 6-Et 188-190 I-a-18Me Me Et 4-Me, 6-Me 176-177 I-a-19 Me Et Et 4-Me, 6-Et 194-195 I-a-20 MeEt Et 4-Me 148-149 I-a-21 Me Et Et 4-Me, 6-Me 188-189 I-a-22 Me Et Me4-Me, 6-Me 210-211 I-a-23 Me i-Pr Et 4-Me, 6-Et 208-210 I-a-24 Me Pr Et4-Me, 6-Et 175-176 I-a-25 Me Et Et 4-Et, 6-Et 170-171 I-a-26 Me Pr Et4-Et, 6-Et 174-175 I-a-27 Me Me Et 4-Et 178-180 I-a-28 Me Et Et 4-Et163-164 I-a-29 Me Me Et 4-Et, 6-Me 168-169 I-a-30 Me Me Et 6-Et 187-188

EXAMPLE 3 5-Benzoyloxy-4-(2-ethylphenyl)-2-methyl-3(2H)-pyridazinone(Compound I-b-1)

To 0.326 g of Compound I-a-1 were added 12 mL of tetrahydrofuran and0.40 mL of triethylamine. The mixture obtained was chilled with ice, towhich 0.25 mL of benzoyl chloride was further added. The mixture wasstirred for 10 minutes under cooling with ice and then at roomtemperature for 3 hours. 30 mL of water was added to the reactionmixture, which was extracted with 30 mL of ethyl acetate twice. Theextracts were combined, washed with a saturated sodium chloride aqueoussolution and dried over anhydrous magnesium sulfate, and the solvent wasdistilled off. The residue was subjected to a silica gel columnchromatography (as eluent, ethyl acetate:hexane=1:2, and then 2:1) toyield 0.463 g of the title compound as colorless oil.

The present compound which was produced according to Example 3 will beshown in Table 3.

The compound represented by the formula (I-b):

TABLE 3 Compound R¹ R² Z¹ (Z²)_(n) G³ m.p./° C. I-b-1 Me H Et — COPh *I-b-2 Me H Et — COMe 69-70 I-b-3 Me H Et — COEt * I-b-4 Me H Et — COi-Pr 77-79 I-b-5 Me H Et — CO t-Bu 56-59 I-b-6 Me H Et — CO c-Hex *I-b-7 Me H Et — CO₂Me 81-82 I-b-8 Me H Et — CONMe₂ * I-b-9 Me H Et —SO₂Me * I-b-10 Me H Pr — COMe 78-79 I-b-11 Me H Me 4-Me, 6-Me CO t-Bu93-96 I-b-12 Me H Et 4-Me, 6-Et COMe  99-101 I-b-13 Me Me Me 4-Me, 6-MeCOMe 130-131 I-b-14 Me Me Et 4-Me, 6-Et COMe 133-134 I-b-15 Me Me Et4-Me, 6-Et CO t-Bu 105-106 I-b-16 Me Me Et — COMe 148-149 I-b-17 Me MeEt — CO t-Bu  89 I-b-18 Me Me Et 4-Me, 6-Et CO₂Et 73-74 I-b-19 Me Me Et4-Me, 6-Et COPh 145-146 I-b-20 Me Me Et 4-Me COMe 142-143 I-b-21 Me MeEt 4-Et, 6-Et COMe 103-104 I-b-22 Me Me Et 4-Me, 6-Me COMe 106-107I-b-23 Me Me Et 4-Me, 6-Et COEt 103-104 I-b-24 Me Me Et 4-Me, 6-Et COi-Pr 102-103 I-b-25 Me Me Et 4-Me, 6-Et CO₂Me 95-96 I-b-26 Me Me Et4-Me, 6-Et CO₂Ph 105 I-b-27 Me Me Et 4-Me, 6-Et SO₂Me 153-154 I-b-28 MeMe Et 4-Me, 6-Et SO₂CF₃ 63-67 I-b-29 Me Et Et 4-Me, 6-Et COMe 133-134I-b-30 Me Pr Et 4-Me, 6-Et COMe 161-162 I-b-31 Me i-Pr Et 4-Me, 6-EtCOMe 159-160 I-b-32 Me Et Et 4-Et, 6-Et COMe 117-118 I-b-33 Me Me Et4-Et COMe 115-116

Concerning the compound which is marked with * in the column m.p. ofTable 3, ¹H-NMR data will be shown below.

Compound I-b-1:

¹H-NMR (CDCl₃) δ ppm: 1.14 (3H, t, J=7.7 Hz), 2.45-2.62 (2H, m), 3.88(3H, s), 7.09-7.12 (1H, m), 7.15-7.20 (1H, m), 7.28-7.30 (2H, m),7.37-7.42 (2H, m), 7.55-7.60 (1H, m), 7.81-7.84 (2H, m), 7.95 (1H, s).

Compound I-b-3:

¹H-NMR (CDCl₃) δ ppm: 0.94 (3H, t, J=7.6 Hz), 1.13 (3H, t, J=7.7 Hz),2.27 (2H, dq, J=1.4, 7.6 Hz), 2.38-2.56 (2H, m), 3.84 (3H, s), 7.00-7.03(1H, m), 7.18-7.23 (1H, m), 7.30-7.35 (2H, m), 7.75 (1H, s).

Compound I-b-6:

¹H-NMR (CDCl₃) δ ppm: 1.13 (3H, t, J=7.7 Hz), 1.10-1.22 (5H, m), 1.5-1.7(5H, m), 2.28 (1H, br.), 2.38-2.55 (2H, m), 3.84 (3H, s), 6.99-7.02 (1H,m), 7.17-7.22 (1H, m), 7.29-7.36 (2H, m), 7.72 (1H, s).

Compound I-b-8:

¹H-NMR (CDCl₃) δ ppm: 1.11 (3H, t, J=7.7 Hz), 2.40-2.57 (2H, m), 2.64(3H, s), 2.85 (3H, s), 3.83 (3H, s), 7.05-7.08 (1H, m), 7.19-7.24 (1H,m), 7.30-7.36 (2H, m), 7.95 (1H, s).

Compound I-b-9:

¹H-NMR (CDCl₃) δ ppm: 1.18 (3H, t, J=7.6 Hz), 2.43-2.57 (2H, m), 2.58(3H, s), 3.85 (3H, s), 7.16-7.19 (1H, m), 7.25-7.30 (1H, m), 7.36-7.43(2H, m), 7.96 (1H, s).

A typical example of the preparation of the compound represented by theformula (II) is shown in Reference example 1.

REFERENCE EXAMPLE 14-(2-Ethylphenyl)-5-methoxy-2-methyl-3(2H)-pyridazinone (Compound II-1)

To a mixture of 2.516 g of4-chloro-5-methoxy-2-methyl-3(2H)-pyridazinone, 2.575 g of2-ethylphenylboronic acid and 3.333 g of sodium carbonate were added 30mL of 1,4-dioxane and 20 mL of water. To the mixture were added 2.417 gof tetrabutylammonium bromide and 0.657 g oftetrakis(triphenylphosphine)palladium, and then under a nitrogenatmosphere, the resulting mixture was stirred and heated under refluxfor 17 hours. After cooling, 50 mL of water was added to the reactionmixture, which was extracted with 100 mL of ethyl acetate and then 30 mLof ethyl acetate. The extracts were combined, washed with a saturatedsodium chloride aqueous solution and dried over anhydrous magnesiumsulfate, and the solvent was distilled off. The solid obtained waswashed with a mixed solvent of ethyl acetate and hexane (1:2) to yield3.238 g of the title compound as yellow crystals.

The compound which was produced according to Reference example 1 will beshown in Table 4.

The compound represented by the formula (II):

TABLE 4 Compound R¹ R² Z¹ (Z²)_(n) R⁷ m.p./° C. II-1 Me H Et — Me127-130 II-2 Et H Et — Me * II-3 i-Pr H Et — Me 121-123 II-4 MeOCH₂CH₂ HEt — Me * II-5 Me H Pr — Me 86-88 II-6 Me H Me 6-Me Me 187-189 II-7 Me HEt 6-Me Me * II-8 Me H Et 6-Et Me 165-166 II-9 Me H Me 4-Me Me 141-142II-10 Me H Me 4-Me, 6-Me Me 186-192 II-11 Et H Me 4-Me, 6-Me Me 100-102II-12 Me H Et 4-Me, 6-Et Me 147-149

Concerning the compound which is marked with * in the column m.p. ofTable 4, ¹H-NMR data will be shown below.

Compound II-2:

¹H-NMR (CDCl₃) δ ppm: 1.12 (3H, t, J=7.7 Hz), 1.39 (3H, t, J=7.3 Hz),2.40-2.53 (2H, m), 3.81 (3H, s), 4.19-4.30 (2H, m), 7.10 (1H, d, J=7.6Hz), 7.21-7.26 (1H, m), 7.30-7.33 (2H, m), 7.88 (1H, s).

Compound II-4:

¹H-NMR (CDCl₃) δ ppm: 1.12 (3H, t, J=7.7 Hz), 2.38-2.52 (2H, m), 3.38(3H, s), 3.82 (3H, s), 3.77-3.84 (2H, m), 4.40 (2H, t, J=5.6 Hz), 7.11(1H, d, J=7.6 Hz), 7.21-7.26 (1H, m), 7.30-7.34 (2H, m), 7.90 (1H, s).

Compound II-7:

¹H-NMR (CDCl₃) δ ppm: 1.08 (3H, t, J=7.7 Hz), 2.07 (3H, s), 2.30-2.45(2H, m), 3.81 (3H, s), 3.82 (3H, s), 7.10 (1H, d, J=7.6 Hz), 7.13 (1H,d, J=7.6 Hz), 7.24 (1H, t, J=7.6 Hz), 7.85 (1H, s).

A typical example of the preparation of the compound represented by theformula (V-a) is shown in Reference example 2.

REFERENCE EXAMPLE 2 2-Propylphenylboronic acid

15.5 mL of butyl lithium (1.6 mol/L solution in hexane) was placed in areaction vessel, which was chilled in a dry ice-acetone bath. To thiswas added a solution of 4.412 g of 2-propylbromobenzene in 45 mL oftetrahydrofuran at −70° C. dropwise over 85 minutes under a nitrogenatmosphere. The mixture was stirred at −70° C. for 30 minutes, to which3.75 mL of trimethyl borate was then added at −70° C. dropwise over 15minutes. The mixture was stirred at −70° C. for one hour and then atroom temperature for 18 hours. To the reaction mixture was added 33 mLof 2N hydrochloric acid dropwise over 10 minutes and then the mixturewas stirred at room temperature for 4 hours. To the mixture was added 20mL of water, which was extracted with 70 mL of ethyl acetate. Theextract was washed with a saturated sodium chloride aqueous solution anddried over anhydrous magnesium sulfate, and the solvent was distilledoff. The residue was subjected to a silica gel column chromatography (aseluent, ethyl acetate:hexane=1:2, and then 2:1) to yield 1.641 g of thetitle compound as colorless crystals.

¹H-NMR (CDCl₃) δ ppm: 1.01 (3H, t, J=7.4 Hz), 1.69-1.79 (2H, m),3.15-3.20 (2H, m), 4.0-6.0 (2H, br.), 7.28-7.33 (2H, m), 7.47 (1H, dt,J=1.5, 7.6 Hz), 8.20-8.23 (1H, m).

Among the compounds represented by the formula (V-a), the following oneswere produced by the manner similar to Reference example 2.

2-Ethyl-6-methylphenylboronic acid

m.p.: 90-91° C.

¹H-NMR (CDCl₃) δ ppm: 1.22 (3H, t, J=7.6 Hz), 2.35 (3H, s), 2.64 (2H, q,J=7.6 Hz), 4.0-5.5 (2H, br.), 6.98 (1H, d, J=7.7 Hz), 7.01 (1H, d, J=7.7Hz), 7.18 (1H, t, J=7.7 Hz).

2,6-Diethyl-4-methylphenylboronic acid

m.p.: 111-113° C.

¹H-NMR (CDCl₃) δ ppm: 1.23 (6H, t, J=7.7 Hz), 2.31 (3H, s), 2.63 (4H, q,J=7.7 Hz), 4.0-5.0 (2H, br.), 6.88 (2H, s).

A typical example of the preparation of the compound represented by theformula (VI) is shown in Reference example 3.

REFERENCE EXAMPLE 3 Ethyl2-[2-(2,6-diethyl-4-methylphenylacetyl)-2-methylhydrazono]propanoate(Compound VI-2)

1.5 g of potassium carbonate was added to a solution of 2.0 g of ethyl2-(methylhydrazono)propanoate in 35 mL of acetonitrile. The mixture wasstirred under cooling with ice, to which a solution of 2.6 g of2,6-diethyl-4-methylphenylacetyl chloride in 10 mL of acetonitrile wasadded dropwise over about 20 minutes. The resulting mixture was furtherstirred for 3.5 hours at room temperature, and then concentrated underreduced pressure. To the residue obtained was added 20 mL of ice-water,which was extracted with ethyl acetate (20 mL×3). The extracts werecombined, washed with a saturated sodium chloride aqueous solution (20mL×2), dried over anhydrous magnesium sulfate and concentrated underreduced pressure. The residue obtained was subjected to basic aluminacolumn chromatography (ethyl acetate:hexane=1:3 as eluent) to yield 1.9g of the title compound as white crystals.

The compound which was produced according to Reference example 3 will beshown in Table 5.

The compound represented by the formula (VI):

TABLE 5 Compound R¹ R² Z¹ (Z²)_(n) R⁹ m.p./° C. VI-1 Me Me Me 4-Me, 6-MeEt 90-91 VI-2 Me Me Et 4-Me, 6-Et Et 73-76 VI-3 Me Me Et — Et * VI-4 MeMe Et 4-Me Et * VI-5 Me Me Et 4-Et, 6-Et Et 63-66 VI-6 Me Me Et 4-Me,6-Me Et * VI-7 Me Et Et 4-Me, 6-Et Et * VI-8 Me Et Et 4-Me Et * VI-9 MeEt Et 4-Me, 6-Me Et * VI-10 Me Et Me 4-Me, 6-Me Et * VI-11 Me i-Pr Et4-Me, 6-Et Et * VI-12 Me Pr Et 4-Me, 6-Et Et * VI-13 Me Et Et 4-Et, 6-EtEt * VI-14 Me Pr Et 4-Et, 6-Et Et * VI-15 Me Me Et 4-Et Et * VI-16 Me EtEt 4-Et Et * VI-17 Me Me Et 4-Et, 6-Me Et * VI-18 Me Me Et 6-Et Et *

Concerning the compound which is marked with * in the column m.p. ofTable 5, ¹H-NMR data will be shown below.

Compound VI-3:

¹H-NMR (CDCl₃) δ ppm: 1.19 (3H, t, J=7.6 Hz), 1.37 (3H, t, J=7.2 Hz),2.20 (3H, br. s), 2.67 (2H, q, J=7.7 Hz), 3.37 (3H, br. s), 4.03 (2H,br. s), 4.33 (2H, q, J=7.0 Hz), 7.06-7.30 (4H, m).

Compound VI-4:

¹H-NMR (CDCl₃) δ ppm: 1.18 (3H, t, J=7.6 Hz), 1.37 (3H, t, J=7.2 Hz),2.20 (3H, br. s), 2.30 (3H, s), 2.63 (2H, q, J=7.7 Hz), 3.36 (3H, br.s), 3.99 (2H, br. s), 4.33 (2H, q, J=7.1 Hz), 6.93 (1H, br. d, J=7.1Hz), 7.00 (1H, br. s), 7.12 (1H, br. d, J=7.8 Hz).

Compound VI-6:

¹H-NMR (CDCl₃) δ ppm: 1.16 (3H, t, J=7.7 Hz), 1.36 (3H, t, J=7.2 Hz),2.22 (3H, s), 2.27 (3H, s), 2.30 (3H, br. s), 2.56 (2H, q, J=7.7 Hz),3.39 (3H, br. s), 4.02 (2H, br. s), 4.32 (2H, q, J=7.1 Hz), 6.86 (2H,br. s).

Compound VI-7(E/Z Mixture):

¹H-NMR(CDCl₃) δ ppm: 1.13-1.25 (9H, m), 1.31-1.41 (3H, m), 2.29 (3H, s),2.50-2.81 (6H, m), 3.23, 3.43 (3H, each br. s), 4.05 (2H, br. s),4.27-4.39 (2H, m), 6.89 (2H, s).

Compound VI-8(E/Z Mixture):

¹H-NMR(CDCl₃) δ ppm: 1.06-1.22 (6H, m), 1.31-1.40 (3H, m), 2.30, 2.31(3H, each s), 2.50-2.70 (4H, m), 3.22, 3.38 (3H, each s), 4.00 (2H, br.s), 4.27-4.37 (2H, m), 6.90-6.98 (1H, m), 6.98-7.02 (1H, m), 7.02-7.14(1H, m).

Compound VI-9(E/Z Mixture):

¹H-NMR(CDCl₃) δ ppm: 1.12-1.25 (6H, m), 1.31-1.41 (3H, m), 2.22 (3H, s),2.27 (3H, s), 2.50-2.81 (4H, m), 3.23, 3.43 (3H, each br. s), 4.02 (2H,br. s), 4.26-4.37 (2H, m), 6.87 (2H, br. s).

Compound VI-10(E/Z Mixture):

¹H-NMR (CDCl₃) δ ppm: 1.16-1.24 (3H, m), 1.32-1.40 (3H, m), 2.22 (6H,s), 2.25 (3H, s), 2.55-2.80 (2H, m), 3.23, 3.43 (3H, each br. s), 4.00(2H, br. s), 4.27-4.38 (2H, m), 6.85 (2H, s).

Compound VI-11:

¹H-NMR (CDCl₃) δ ppm: 1.18 (6H, t, J=7.6 Hz), 1.24 (6H, d, J=6.8 Hz),1.37 (3H, t, J=7.1 Hz), 2.29 (3H, s), 2.55 (4H, q, J=7.6 Hz), 2.85 (1H,septet, J=6.8 Hz), 3.22 (3H, s), 4.04 (2H, s), 4.34 (2H, q, J=7.2 Hz),6.88 (2H, s).

Compound VI-12(E/Z Mixture):

¹H-NMR (CDCl₃) δ ppm: 1.01 (3H, t, J=7.4 Hz), 1.17 (6H, t, J=7.6 Hz),1.31-1.40 (3H, m), 1.57-1.74 (2H, m), 2.30 (3H, s), 2.50-2.76 (6H, m),3.22, 3.42 (3H, each s), 4.03, 4.05 (2H, each br. s), 4.26-4.36 (2H, m),6.89 (2H, s).

Compound VI-13(E/Z Mixture):

¹H-NMR (CDCl₃) δ ppm: 1.13-1.28 (12H, m), 1.30-1.40 (3H, m), 2.50-2.80(8H, m), 3.23, 3.44 (3H, each s), 4.06 (2H, br. s), 4.28-4.39 (2H, m),6.91 (2H, s).

Compound VI-14(E/Z Mixture):

¹H-NMR (CDCl₃) δ ppm: 1.01 (3H, br. t, J=7.2 Hz), 1.13-1.26 (9H, m),1.30-1.40 (3H, m), 1.56-1.73 (2H, m), 2.50-2.76 (8H, m), 3.22, 3.42 (3H,each s), 4.03, 4.06 (2H, each br. s), 4.26-4.37 (2H, m), 6.91 (2H, s).

Compound VI-15:

¹H-NMR (CDCl₃) δ ppm: 1.15-1.25 (6H, m), 1.37 (3H, t, J=7.2 Hz), 2.20(3H, br. s), 2.55-2.70 (4H, m), 3.36 (3H, br. s), 3.99 (2H, br. s), 4.33(2H, q, J=7.1 Hz), 6.96 (1H, br. d, J=7.3 Hz), 7.02 (1H, br. s), 7.15(1H, br. d, J=7.8 Hz).

Compound VI-16(E/Z Mixture):

¹H-NMR(CDCl₃) δ ppm: 1.05-1.25 (9H, m), 1.32-1.40 (3H, m), 2.50-2.69(6H, m), 3.22, 3.38 (3H, each s), 4.00 (2H, br. s), 4.26-4.36 (2H, m),6.93-7.00 (1H, m), 7.00-7.04 (1H, m), 7.06-7.18 (1H, m).

Compound VI-17:

¹H-NMR (CDCl₃) δ ppm: 1.17 (3H, t, J=7.6 Hz), 1.22 (3H, t, J=7.6 Hz),1.36 (3H, t, J=7.1 Hz), 2.24 (3H, s), 2.30 (3H, br. s), 2.58 (4H, q,J=7.6 Hz), 3.40 (3H, br. s), 4.03 (2H, br. s), 4.32 (2H, q, J=7.2 Hz),6.89 (2H, s).

Compound VI-18:

¹H-NMR (CDCl₃) δ ppm: 1.19 (6H, t, J=7.6 Hz), 1.36 (3H, t, J=7.2 Hz),2.32 (3H, br. s), 2.60 (4H, q, J=7.7 Hz), 3.40 (3H, br. s), 4.09 (2H,br. s), 4.33 (2H, q, J=7.2 Hz), 7.07 (2H, d, J=7.6 Hz), 7.18 (1H, t,J=7.6 Hz).

FORMULATION EXAMPLE 1 Emulsifiable Concentrate

Compound I-a-1 20% by weight polyoxyethylene alkyl ether 5% by weightdimethylformamide 18% by weight and xylene 57% by weightare mixed to yield an emulsifiable concentrate. The emulsifiableconcentrate prepared is used after properly diluted with water.Compounds I-a-2 to I-a-23 and I-b-1 to I-b-23 instead of Compound I-a-1are similarly formulated to yield the emulsifiable concentrate for eachcompound.

FORMULATION EXAMPLE 2 Wettable Powder

Compound I-b-2 50% by weight sodium lignin sulfonate 5% by weightpolyoxyethylene alkyl ether 5% by weight white carbon 5% by weight andclay 35% by weightare pulverized and mixed to yield wettable powder. The wettable powderprepared is used after properly diluted with water.

FORMULATION EXAMPLE 3 Granule

Compound I-a-12 1.5% by weight sodium lignin sulfonate 2% by weight talc40% by weight and bentonite 56.5% by weightare mixed, kneaded with water and palletized to yield granules.

FORMULATION EXAMPLE 4

Ten parts of Compound (I-a-12), 10 parts of any one of the compoundselected from the following Group A, 4 parts of sodium laurylsulfate, 2parts of calcium ligninsulfonate, 20 parts of synthetic hydrated silicaand 54 parts of diatomaceous earth are pulverized and mixed well to giveeach wettable powders.

Group A

2,4-PA, MCP, MCPB, phenothiol, mecoprop, fluroxypyr, triclopyr,clomeprop, naproanilide,

2,3,6-TBA, dicamba, clopyralid, picloram, aminopyralid, quinclorac,quinmerac,

diuron, linuron, chlortoluron, isoproturon, fluometuron, isouron,tebuthiuron, methabenzthiazuron, cumyluron, daimuron, methyl-daimuron,

atrazine, ametoryn, cyanazine, simazine, propazine, simetryn,dimethametryn, prometryn, metribuzin, triaziflam,

paraquat, diquat,

bromoxynil, ioxynil,

pendimethalin, prodiamine, trifluralin,

amiprofos-methyl, butamifos, bensulide, piperophos, anilofos,glyphosate, glufosinate, bialaphos,

di-allate, tri-allate, EPIC, butylate, benthiocarb, esprocarb, molinate,dimepiperate, swep, chlorpropham, phenmedipham, phenisopham,pyributicarb, asulam,

propanil, propyzamide, bromobutide, etobenzanid,

acetochlor, alachlor, butachlor, dimethenamid, propachlor, metazachlor,metolachlor, pretilachlor, thenylchlor, pethoxamid,

acifluorfen-sodium, bifenox, oxyfluorfen, lactofen, fomesafen,chlomethoxynil, aclonifen,

oxadiazon, cinidon-ethyl, carfentrazone-ethyl, surfentrazone,flumiclorac-pentyl, flumioxazin, pyraflufen-ethyl, oxadiargyl,pentoxazone, fluthiacet-methyl, butafenacil, benzfendizone,

benzofenap, pyrazolate, pyrazoxyfen, topramezone, pyrasulfotole,

isoxaflutole, benzobicyclon, sulcotrione, mesotrione, tembotrione,tefuryltrione,

clodinafop-propargyl, cyhalofop-butyl, diclofop-methyl,fenoxaprop-ethyl, fluazifop-butyl, haloxyfop-methyl, quizalofop-ethyl,metamifop,

alloxydim-sodium, sethoxydim, butroxydim, clethodim, cloproxydim,cycloxydim, tepraloxydim, tralkoxydim, profoxydim,

chlorsulfuron, sulfometuron-methyl, metsulfuron-methyl,chlorimuron-ethyl, tribenuron-methyl, triasulfuron, bensulfuron-methyl,thifensulfuron-methyl, pyrazosulfuron-ethyl, primisulfuron-methyl,nicosulfuron, amidosulfuron, cinosulfuron, imazosulfuron, rimsulfuron,halosulfuron-methyl, prosulfuron, ethametsulfuron-methyl,triflusulfuron-methyl, flazasulfuron, cyclosulfamuron, flupyrsulfuron,sulfosulfuron, azimsulfuron, ethoxysulfuron, oxasulfuron,iodosulfuron-methyl-sodium, foramsulfuron, mesosulfuron-methyl,trifloxysulfuron, tritosulfuron,

imazamethabenz-methyl, imazamethapyr, imazamox, imazapyr, imazaquin,imazethapyr, orthosulfamuron, flucetosulfuron,

flumetsulam, metosulam, diclosulam, florasulam, cloransulam-methyl,penoxsulam, pyroxsulam,

pyrithiobac-sodium, bispyribac-sodium, pyriminobac-methyl, pyribenzoxim,pyriftalid, pyrimisulfan,

bentazon, bromacil, terbacil, chlorthiamid, isoxaben, dinoseb, amitrole,cinmethylin, tridiphane, dalapon, diflufenzopyr-sodium, dithiopyr,thiazopyr, flucarbazone-sodium, propoxycarbazone-sodium, mefenacet,flufenacet, fentrazamide, cafenstrole, indanofan, oxaziclomefone,benfuresate, ACN, pyridate, chloridazon, norflurazon, flurtamone,diflufenican, picolinafen, beflubutamid, clomazone, amicarbazone,pinoxaden, pyraclonil, pyroxasulfone, thiencarbazone-methyl,

furilazole, dichlormid, benoxacor, allidochlor, isoxadifen-ethyl,fenchlorazole-ethyl, mefenpyr-diethyl, cloquintocet-mexyl, fenclorim,cyprosulfamide, cyometrinil, oxabetrinil, fluxofenim, flurazole and1,8-naphthalic anhydride.

FORMULATION EXAMPLE 5

Ten parts of Compound (I-a-13), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 6

Ten parts of Compound (I-a-14), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 7

Ten parts of Compound (I-a-15), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 8

Ten parts of Compound (I-a-16), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 9

Ten parts of Compound (I-a-17), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 10

Ten parts of Compound (I-a-18), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 11

Ten parts of Compound (I-a-19), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 12

Ten parts of Compound (I-b-12), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 13

Ten parts of Compound (I-b-14), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 14

Ten parts of Compound (I-b-16), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 15

Ten parts of Compound (I-b-18), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 16

Ten parts of Compound (I-b-19), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 17

Ten parts of Compound (I-b-20), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 18

Ten parts of Compound (I-b-21), 10 parts of any one of the compoundselected from the above-mentioned Group A, 4 parts of sodiumlaurylsulfate, 2 parts of calcium ligninsulfonate, 20 parts of synthetichydrated silica and 54 parts of diatomaceous earth are pulverized andmixed well to give each wettable powders.

FORMULATION EXAMPLE 19

Ten parts of each of Compound (I-a-12), (I-a-13), (I-a-14), (I-a-15),(I-a-16), (I-a-17), (I-a-18), (I-a-19), (I-b-12), (I-b-14), (I-b-16),(I-b-18), (I-b-19), (I-b-20) or (I-b-21); 10 parts of flumioxazine; 4parts of sodium laurylsulfate; 2 parts of calcium ligninsulfonate; 20parts of synthetic hydrated silica and 54 parts of diatomaceous earthare pulverized and mixed well to give each wettable powders.

FORMULATION EXAMPLE 20

Five parts of each of Compound (I-a-12), (I-a-13), (I-a-14), (I-a-15),(I-a-16), (I-a-17), (I-a-18), (I-a-19), (I-b-12), (I-b-14), (I-b-16),(I-b-18), (I-b-19), (I-b-20) or (I-b-21); 25 parts of glyphosate; 4parts of sodium laurylsulfate; 2 parts of calcium ligninsulfonate; 20parts of synthetic hydrated silica and 44 parts of diatomaceous earthare pulverized and mixed well to give each wettable powders.

TEST EXAMPLE 1 Post-Emergence Treatment Test in Dry Field

A plastic cup with a diameter of 8 cm and a depth of 6.5 cm was filledwith commercially available soil, onto which seeds of Lolium multiflorumwere sowed, covered with soil about 0.5 cm high and then grown in agreenhouse. When the plants were grown in first to second leaf stage, aprescribed dosage of a dilute liquid formulation comprising CompoundI-a-1 was sprayed to whole plants uniformly. The dilute liquidformulation was prepared by dissolving a prescribed amount of CompoundI-a-1 in a dimethylformamide solution (2%) of Tween 20 (polyoxyethylenesorbitan fatty acid ester, from MP Biomedicals, Inc.) and then dilutingwith deionized water. The plants after treatment with the liquidformulation were grown in a greenhouse and 20 days after the treatment,the efficacy of the compound against Lolium multiflorum was visuallyevaluated by rating in eleven levels from 0 to 10 (assigned as 0 for noeffect and 10 for complete death while values falling in between thesevalues were rated from 1 to 9 levels accordingly).

The other present compounds and Compound A described in J. Heterocycl.Chem., vol. 42, pp. 427-435 (2005) as a comparative example weresimilarly tested.

COMPARATIVE EXAMPLE Compound A

As a result, Compounds I-a-1, I-a-5, I-a-6, I-a-7, I-a-8, I-a-9, I-a-12,I-b-1, I-b-2, I-b-4, I-b-5, I-b-7, I-b-10 and I-b-11 showed the effectequal to 7 or more at a treatment dosage of 500 g/ha, whereas CompoundsI-a-13, I-a-14, I-a-15, I-a-16, I-a-17, I-a-18, I-a-19, I-a-20, I-a-21,I-a-22, I-a-27, I-b-12, I-b-13, I-b-14, I-b-16, I-b-17, I-b-18, I-b-20,I-b-21, I-b-22, I-b-23 and I-b-25 showed the effect equal to 7 or moreat a treatment dosage of 250 g/ha. By contrary, Compound A showed theeffect to be 1 at a treatment dosage of 500 g/ha.

TEST EXAMPLE 2 Pre-Emergence Treatment Test in Dry Field

A plastic container (32 cm×22 cm×8 cm in height) was filled with soilsterilized by steam, onto which seeds of Apera spica-venti were sowedand covered with soil about 0.5 cm high. A prescribed dosage of a diluteliquid formulation comprising Compound I-a-1 was sprayed to the soilsurface uniformly. The dilute liquid formulation was prepared by themethod similar to that in Test example 1. The plants after treatmentwith the liquid formulation were grown in a greenhouse and three weeksafter the treatment, the efficacy of the compound against Aperaspica-venti was visually evaluated by rating in eleven levels from 0 to10 similarly to Test example 1.

The other present compounds and Compound A as a comparative example weresimilarly tested.

As a result, Compounds I-a-1, I-a-2, I-a-4, I-a-5, I-a-6, I-a-8, I-a-9,I-a-10, I-b-1, I-b-5, I-b-6, I-b-7 and I-b-11 showed the effect equal to8 or more at a treatment dosage of 500 g/ha, whereas Compounds I-a-12,I-a-13, I-a-14, I-a-15, I-a-16, I-a-17, I-a-18, I-a-19, I-a-20, I-a-21,I-a-22, I-a-23, I-b-13, I-b-14, I-b-16, I-b-18, I-b-19, I-b-20, I-b-21,I-b-22 and I-b-23 showed the effect equal to 8 or more at a treatmentdosage of 250 g/ha. By contrary, Compound A showed the effect to be 1 ata treatment dosage of 500 g/ha.

INDUSTRIAL APPLICABILITY

The present compound has an excellent effect on weed control and isuseful as an active ingredient of herbicides.

1-15. (canceled)
 16. A compound represented by the formula (VI):

wherein in the formula, R⁹ represents a C₁₋₆ alkyl group, R¹ representsa C₁₋₆ alkyl group or a (C₁₋₆ alkyloxy) C₁₋₆ alkyl group, R² representsa C₁₋₆ alkyl group, Z¹ represents a C₁₋₆ alkyl group, Z² represents aC₁₋₆ alkyl group, n represents 0, 1, 2, 3 or 4 and each of Z² may besame or different when n represents an integer of 2 or more, and a sumof the number of carbon atoms in the group represented by Z¹ and that inthe group represented by Z² is equal to 2 or more.
 17. The pyridazinonecompound according to claim 16, wherein n is an integer equal to 1 ormore.
 18. The pyridazinone compound according to claim 16, wherein n is0 and Z¹ is a C₂₋₆ alkyl group.
 19. The pyridazinone compound accordingto claim 16, wherein n is 1 or 2 and Z² is (a) substituent(s) on 4-and/or 6-position of a benzene ring.
 20. The pyridazinone compoundaccording to claim 16, wherein Z¹ is a C₁₋₃ alkyl group and Z² is a C₁₋₃alkyl group.
 21. The pyridazinone compound according to claim 16,wherein R² is a C₁₋₃ alkyl group.
 22. The pyridazinone compoundaccording to claim 16, wherein R² is a methyl group.
 23. Thepyridazinone compound according to claim 16, wherein R¹ is a C₁₋₃ alkylgroup or a (C₁₋₃ alkyloxy) C₁₋₃ alkyl group.